Abaddon/Abadon (FF8/FF10): "Abaddon" is Hebrew for "destroyer". "They had as king over them the angel of the Abyss, whose name in Hebrew is Abaddon, and in Greek, Apollyon." -Rev 9:10. The end of the verse quoted refers to the same name being a "locust king", and Abaddon does resemble an insect.
Achelous (FF10): Achelous is a Greek river god. Said to be the father of the Sirens (singing water nymphs).
Actaneon (FF6): Probably a variant spelling of "actinia", a kind of sea anemone. It comes from the Greek for "ray".
Adamantoise (various): See Items. Adamant is from the Greek 'adamantos', but the '-oise' suffix comes from the word 'tortoise'.
Adramelk (FFT/FFTA): See Adramelk (FF:Tactics).
Aeshma (FFX2): This is a Daeva of vengeance, the basis for the demon Asmodeus in Jewish lore. Aeshma is a Persian archdemon of violence and anger.
Agama (FFX2): The name comes from the small, insect-eating lizards of the same name of the family Agamaide, found in European tropics.
Agaliarept (FF3): This demon was mentioned in "Verum or The True Grimoire The Most Approved Keys of Solomon, The Hebrew Rabbi" and later in "Le Veritable Dragon Rouge", which provided a picture of him.
Agares (FF9): Number 2 of the 72 Goetia, or Lesser Key of Solomon. The Goetia were said to have been imprisoned in a magic ring and cast into a lake. Here’s what is says about him in the Goetia: "Agares is the Second Spirit listed in the Goetia. He is Duke under the Power of the East and governs 31 legions. He appears as an old man riding on a crocodile & carrying a Goshawk in his hand. He can teach languages, destroy Dignities, and cause earthquakes."
Ahriman: Ahriman is the god of evil and darkness, in opposition to Ahura Mazda, in the Zoroastrian religion.
Aka Manah (FFX2): This is a Daeva who is the personification of lust. The name means "evil mind"; this demon was supposed to be at eternal opposition to Vohu Manah ("good mind") in Persian mythology, and they both represent the good and evil forces in life.
Alcyone (FF10): In Greek Mythology, Alcyone, who in grief over the death of her husband Ceyx, threw herself into the sea and was changed into a halcyon; a bird identified with the kingfisher, believed to have had the power to calm the wind and the waves at the time of the winter solstice when it nested on the sea. Halcyon means tranquil and free from disturbance or care; prosperous; golden: as in "halcyon years". Other versions make Alcyone, and her six sisters, the daughters of Atlas. Some said that it was because of the daughters' grief over Atlas, their father, whose labor in bearing the world, was the cause of their transformation and subsequent transfer to the heavens.
Alte Roit (FF5): "Alte" is German for "old" or "ancient", and "roit" is French for "king" - hence, Alte Roit = Ancient King.
Amdusias (FF9): Amdusius is a slight adaptation of "Amduscius" - a mythical demon spirit said to resemble a unicorn. References to Amduscias can be found in Johann Wier's "pseudomonarchia daemonum" (1583 A.D.) and later Collin De Plancy's "dictionnaire infernal" (1863 A.D.). The Goetia (see Agares): "Amdusias (Amdukias) is the sixty-seventh Spirit listed in the Goetia, who governs 29 Legions. He appears as a unicorn, but will transform to human shape accompanied by the sounding of trumpets & other musical instruments upon request. He causes trees to bend & decline at the invoker's request."
Anacondaur (FF8): Anaconda + Saurus (dinosaur).
Angra Mainyu (FFX2): This is an alias of Ahriman. The name means "evil mentality".
Antlion: Antlions are a species of predatory insects in Africa. Their larvae dig holes and wait for prey to stumble in for their food. It looks almost identical to the creatures in the games.
Apokryphos (FF6): On the Floating Continent. Its name comes from Greek for "hidden". This is the origin of the English word "apocryphal", which means "almost certainly fictional".
Apsu (FF7): Apsu helped to create the universe along with Tiamat in the Babylonian creation myth.
Aquila (FF6): Latin for 'eagle'.
Arachne (FF4): She was a woman who weaved things and was turned into a spider by Athena when she lost a bet - thus she's a spider in this game (and thus the English word "arachnid").
Archaeoavis (FF5): Archeo is Greek for Ancient, and Avis I assume relates to birds, flight, hence aviary, which literally translates as "ancient bird".
Aspidochelon (FF6): Aspik in FF3. But that ruins the name, since it comes from Greek "aspidion" (a small round shield) and "chelon" (hard shell).
Astaroth (FF2): Astaroth is another fallen angel in league with Lucifer. Astaroth was an early Sidonian and Egyptian goddess of fertility that was condemned as a demon by the Christian Church to covert others from paganism to Christianity.
Axolotl (FF9): This is a type of amphibian which keeps gills into adulthood. It looks the same as the creatures in the game except less upright and it can't kill anything.
Azi Dahaka (FFX2): This is a Daeva dragon, connected to Dahaka. The name means "fiendish snake" in Old Persian; it's a demon that appears as a three-headed snake, and brings storm.
Azulmagia (FF5): Azulmagia (the name of the Blue Mage boss) is Spanish for Blue Magic.
Bandersnatch (FF9): The frumious Bandersnatch comes from Lewis Carroll's poem 'Jabberwocky", quoted in "Alice Through The Looking-Glass".
Barbatos (FF10): The Goetia (see Agares): "Barbatos is the Eighth Spirit listed in the Goetia, a duke who governs 30 Legions of spirits. He usually appears with 4 noble kings & their armies when the Sun is in Sagittary. He can decipher what animals are saying, open magically protected treasures, knows of past things, can predict the future, & can council those in power."
Barbuta (FFX2): A Barbuta is an Italian helmet with no crest. Fitting for one of the armored mole monsters.
Bashura (FF10): Bash (as in hit) + Ashura.
Basilisk (FF10): A reptilian creature of many legends who turns things to stone by its gaze (made popular by Harry Potter and the Chamber of Secrets).
Beelzebub (FF2): Beelzebub is one of the Fallen Angels that is considered a lieutenant to Lucifer. Belzebub is also the Lord of the Flies.
Behemoth (various): Hebrew for "animal", it also entered the English dictionary as meaning "huge creature or thing". Hence the humongous purple dude. A book called The Encyclopedia Of Angels lists Behemoth as "The male counterpart to Leviathan, one of the fallen angels and a demon of the deep. Like Leviathan he is associated with Rahab and the sea, and is personified variously as a whale, crocodile, and hippopotamus. Rabbinic lore holds that on the Day of Judgment, he will slay and be slain by Leviathan."
Berserker (FF3): See Miscellaneous.
Blitz (FF8): "Blitz" is German for "lightning", and since he uses thunder attacks and absorbs it, it makes perfect sense.
Bolfry (FF3): This is another of the Goetia demons. More commonly known as Berith.
Boris(FFX2): This spider monster's name may be a nod to "Boris the Spider" a song by the band, The Who.
Buel (FF8) / Buer (FF10): The Goetia (see Agares): "Buer is the Tenth Spirit listed in the Goetia, who appears in and like Sagittary when the Sun is there. He teaches moral & natural philosophy, logic art, & herbology. He also can calm distempers in man. He governs 50 Legions of Spirits."
Bunyip (FF10): A Bunyip is an Australian water demon known for shapeshifting. It is said to take the form of an emu, a dog, a horse, or a humanoid (Magickal, Mythtical, Mystical Beasts by D.J. Conway) with backwards feet. Others say it is deerlike in appearance with red eyes, webbed feet, and matted black hair and is commonly seen in rivers (Cryptozoology A to Z by Loren Coleman).
Byblos (FF5, Tactics): You meet him in FF5's Library of Ancients, which makes sense since his name is derived from the Greek for "book". The French, German, and Russian words for "library" (and perhaps several others) are all cognates, related to the Greek. FF5's Library of Ancients is patterned after the one in Alexandria, and the two most famous books there were "Byblos" and "Almagest".
Cactuar: Probably a cross between "cactus" and "jaguar" for its ferocity. In Japanese these are known as "sapotenders", which comes from Japanese "sapoten", meaning cactus, and "pretender". And in FF6 NA it was called "Cactrot", adding "trot" to it (perhaps because it always runs away?). In the Japanese, it's not Sabotenders but "Sabotendaa." It's a joke: "Saboten" is indeed cactus and "da" is simply a form of "to be." So, the monster's name WOULD be "It's a Cactus!" (a suitable thing to read when you see one of the bizarre things), but with the long 'a' at the end, it's like "(Almost) It's a Cactus!"
Canis Major (FFX2): The name comes from the constellation of a dog that contains the star Sirius. "Canis" means "dog" in Latin.
Catoblepas (various): Catoblepas comes from Greek mythology as an enormous bull with scales. A catoblepas is supposedly a being who lives in the forests and can turn enemies to stone merely by glancing at them. His attack is called "Akuma no Hitomi" which means "Devil's Eye". "Catoblepas" means "that which looks down". Catoblepas is originally a Lybian Medusa, a bull whose horns were so heavy it couldn't raise its head; thankfully, because its gaze had the power to petrify living beings.
Cephaler (FF6): Comes from the same root as 'cephalopod' and is the class of octopi and squids.
Cerberus (various): The triple-headed dog who guards Tartarus, the Greek version of Purgatory.
Chac (FFX2): Chac is the Mayan god of rain and thunder.
Chimera (various): From Greek mythology. It's a fire-breathing monster having either the hindquarters of a serpent and the head of a lion on the body of a goat, or else the back of a goat, the wings of a dragon, the front half of a lion, and three heads (one each for goat, lion and dragon). In Square games they favor the latter description, adding in a snake for a tail.
Chimerageist (FF10): "Geist" is German for "spirit", so the name means "Chimera Spirit".
Claret Dragon (FFX2): Claret is a dark, purplish red color, which matches the color of the dragon's body.
Cockatrice (various): Supposedly they were deadly winged serpents from biblical times. It is said in a legend that, when the moons are just right, a chicken somewhere will lay an egg. On that night, a snake will appear and curl itself around that egg. When the egg hatches, a fearful monster called a "cockatrice" emerges from it. The monster, half bird and half snake; has the powers of the Gorgon, and can turn people into stone just by people looking at them.
Coeurl (various): The "cuarl" is almost surely based on the "coeurl" from A.E. Van Voght's short story "Black Destroyer". In it, there's an alien creature resembling a panther with tentacles and psionic powers. The Displacer Beast (from Dungeons and Dragons) was also likely based on this monster. There's also a monster called Coeurlregina in FF10, which basically means "Coeurl Queen", "regina" being Latin for "queen".
Daeva (FFX2): A group of demons in the middle east, yet gods in the far-east, especially Hinduism.
Dark Side (FF6): Maybe this has something to do with "the Force" in the Star Wars movies; Darth Vader is on the Dark Side. Probably just coincidence, though.
Demonolith (FF10): Demon + Monolith.
Dingo (FF10): The name of a canine animal indigenous to Australia.
Dream Stooges (FF6): In Japan, their names were Sueño, Sogno, and Rêve. The names mean "dream" in Spanish, Italian, and French, respectively.
Dullahan (FF2, FF6, FFMQ): Dullahan is from Irish mythology, and is a headless spirit that wanders around Ireland, holding his head under his arm and driving a black coach drawn by headless horses! He knocks on people's doors, and hurls a bucket of blood in their faces! A visit from Dullahan is considered to be a portent of death.
Eland (FF6): Shows up not only on the Veldt in FF6, but on the "real" veldt in Africa. It's a big antelope with horns.
Epitaph (FF9): This tombstone-like monster appropriately obtains its name from the general word for inscriptions upon a gravestone.
Espada (FF10): Spanish for "sword".
Fafnir (FF10): The dragon killed by Siegfried in the Ring of the Nibelung Norse legend. See Siegfried for more info. Fafnir also appears in the Japanese version of FF6 (it was translated as Vectaur).
Farfarello (FF5): Shows up in the forest part of the Cleft of Dimension, is another demon from Dante's Inferno. Some of the others
are the Four Fiends in FF2. This monster was translated as "Jestrex" for some reason in the PSX version.
Fastitocalon (FF8): In Tolkien's Middle Earth series, the Fastitocalon were huge turtle-fish monsters in Hobbit lore that were often mistaken for islands.
Fenrir (FF10): See Summons.
Figaliz (FF6): Short for "Figaro Lizard".
Flan (various): This is a type of dessert. Also note the "puddings" and "mousse"s that have variations on this. The monster in FF6 called Muus is in fact supposed to be "mousse". FFX2's Flans each have Spanish names: Amarillo = Yellow, Azabache = Jet Black, Azul (Azule) = Blue, Palido = white wine-grape; pale, Rojo = Red
Fortis (FF6): Comes from Latin and means strength or power.
Frost Giants (FF1): The Frost Giants come from Nordic mythology. The father of the Frost Giants was Ymir, and with his cow Audumla he created the Aesir, and Odin is among them.
Fury (FF5): The Furies were old crones sent by the gods to punish people. Supposedly, they carried whips with thorns on them.
Gandarewa (FF10): Gandarew is a Persian water demon that attempts to devour the good things of creation.
Gargoyles (FF5): Stone statues that are frequently seen near entrances to buildings. They guard the entrances to the places where the slabs are located. Some old European castles would have gargoyles above the door to ward off evil spirits. Goyles and Red Goyles are in FF1 also.
Garm (FF6): In Nordic myths, Garm is a dog who is killed by Tyr at Ragnarok.
Garuda (FF10): The bird that Vishnu rode on in Hindu legend. Garuda is the king of all birds in Hindu mythology and supposedly can carry several gods without impediment. Garuda represents good, and can sense evil in its vicinity.
Gemini (FF10): The Twins of Zodiac fame. The two Iron Giant-type monsters always appear together, hence the name.
Gerogero (FF8): This is a Japanese onomatapoeia word for 'throwing up'.
Gilgame (FF5): 'Gil' is the basic currency of the FF series and 'game' is turtle (ishigame to be more correct, ishigame is various turtles and kame is tortoise or turtle).
Gnoll (FF9): From Dungeons and Dragons, the gnoll is described as a tall desert-dwelling humanoid with the head of a hyena & greyish green fur.
Gnoma Entite (FF12): "Gnoma" comes from "gnome". The gnomes were small dwarf-like creatures who lived in the earth, and were sometimes regarded as being earth spirits.
Grasharaboras (FF6): Known as Borras in the American version. See Summons.
Grendel (FF8, FF10): A monster fought by the legendary Beowulf. See Characters for more info on Beowulf.
Grosspanzer (FF7): This is German for "Grand Armor".
Gucumatz (FFX2): There is a Mayan epic known as the Popol Vuh that contains the tale of a hero named Gucumatz who possesses the ability to trnasform into a variety of animals.
Gug (FFX2): Likely derived of Gog, a giant who with his partner Magog appear in Revelations to symbolize the future enemies of God. Gug is an ogre-like monster from H.P Lovecraft's Cthulu mythos with a giant gaping maw for a head. Minus the maw-for-a-head, FFX-2's Gug fits a similar description.
Halicarnassus (FF5): One of the bosses of the Cleft of Dimension. The name probably comes from the Mausoleum at Halicarnassus, which was
built in what is now Turkey around 350 BC. It was built for Carian king Mausolus; thus the English word "mausoleum". Incidentally, this is another Wonder of the Ancient World. This name was also butchered in the PSX translation as "Halycanos".
Halma (FF10): Greek for "jump".
Haokah (FF3): According to Encyclopedia Mythica, he's the Sioux god of thunder, and sometimes the god of the hunt. That fits given he uses a thunder attack.
Hecteyes (FF2, FF9): English for "hundred eyes".
Hilgigars (FF9): Should be "Hill Gigas".
Hipocampus (FF6): In Greek mythology, a hippocampus was a sea creature that resembled a horse with the lower body of a dolphin or fish. One of these was what pulled Poseidon's chariot.
Hrimthurs (FFX2): Hrimthurs was a god in Norse mythology that constructed the walls surrounding Asgard.
Humpty (FF6): Probably comes from the poem, "Humpty Dumpty".
Hydra (FF4): See Hydra.
Ibises (FF5): An ibis is a type of bird much represented in Egyptian mythology. In the PSX version, though, there were translated as "Avis"es, from the Latin for "to fly". "Tote Avis" could either mean "Death Ibis" ('Tod' (rhymes with boat) is German for 'death') or "Thoth Ibis" (as in the Egyptian god who kept balance in the world, and who had the head of an ibis). Also "Jura Avis/Ibis" may be related to the Jurassic period in history, which is in turn named for the Jura mountains in Switzerland. "Avis" is probably the correct translation, I believe.
Intangir (FF6): Probably from 'intangible'... he's pretty hard to hit! Maou mentions that Intangir was "Nemureru Shishi," "Sleeping Lion," in the Japanese version.
Io (FF6): The name of Jupiter's volcanic moon. Jupiter's four lovers included Io, Europa, Callisto, and Ganymede - they're immortalized as Jupiter's four largest moons. It should be pronounced "EE-oh", but you also hear "EYE-oh". The Columbia Encyclopedia entry for Io: "In Greek mythology, daughter of Inachus, king of Argos. She was loved by Zeus, who, to protect her from Hera's jealousy, changed her into a white heifer. Hera, however, was not deceived; she claimed the heifer and sent Argus to guard it. When Hermes killed Argus, Hera tormented Io with a gadfly which drove her across Europe and through Asia, until she was finally allowed to rest in Egypt. There Zeus returned her to human form, and she bore his child Epaphus. Io has been identified with the Egyptian goddess Isis."
Ironside (FFX2): This may refer to the warship U.S.S. Constitution. In the 1800s, it was referred to as "Old Ironsides". Ironside was a regiment led by Oliver Cromwell during the English Civil War (early 1600s) against King James I.
Jabberwock (FF9): The Jabberwock comes from Lewis Carroll's poem 'Jabberwocky", quoted in "Alice Through The Looking-Glass".
Jahi (FFX2): Jahi is a Persian demoness of debauchery.
Jormungard: See Terrato / Midgard Serpent.
Jubjub (FF11): The Jubjub Bird comes from Lewis Carroll's poem 'Jabberwocky", quoted in "Alice Through The Looking-Glass".
Kary (FF1, FF9): The Fiend of Fire in FF1, Kary could be an alternate spelling of Kali from Indian myths. Kali demanded human sacrifices of her worshipers and had skin blacker than the night sky. She had three eyes, four arms, and giant tusks coming from her mouth. The boss character Kary itself is based on a Hindu goddess. Kali was the three-eyed female counterpart of Shiva the Destroyer in Hindu mythology. When they danced, they wrought destruction upon the world, though they each had the power to keep the other in check and help maintain balance in the universe. Kary was also called Marilith in the JP version, so likely only the name has this origin, the creature was not based on the myth.
Kelpie
King VERMIN!!!(FFX2): The boss's name may be a reference to the part in FF7 where Barrett says to Shinra's president: "...and that makes you King VERMIN!!!".
Kraken (FF1, FF9): A mythical giant squid from Norse and Scandinavian lore. Kraken is also a sea monster. Could be either Scandinavian or Greek in origin. Supposedly a Kraken lies in the Straits of Gibraltar waiting for unlucky ships. The Kraken is widely thought of as being Greek *only* because the monster appeared in the film "Clash of the Titans."
Kulkulcan (FFX2): Kulkulcan was essentially the Mayan version of the Aztec thunder god: Quetzacoatl. It may also be a misspelling of See Queklain/Cuchulainn (Characters).
Kyzoku (FF1): Probably a misspelling of "Kaizoku", Japanese for "pirate".
Lamashtu (FF10): Lamashtu was a Sumerian/Mesopotamian demon that had the head of a lioness and a donkey's body.
Lamia (FF5, FF9): Lamia is Latin for 'lecherous' or a demon, vampire or witch. It is also spoken as a serpent with a woman's breasts and head. Lamia was, in ancient Greek and Roman mythology, a hideous creature who kidnapped and murdered children. She was originally a beautiful woman who was loved by the Gree god Zeus. A jealous Hera snatched away her children and turned her into the creature that she became. The name 'Lamia' was gradually used to categorise a type of child-snatching demon that ate the flesh of its victims. In modern mythology, the lamia is a type of female vampire.
Larry, Curley, Moe (FF6 NA): The three monsters in Cyan's dream are named after The Three Stooges.
Larva (FF10): Besides being a wormy baby thing that insects turn into, it's also a malevolent spirit of the dead in Roman myth.
Lethal Weapon (FF6): Maybe named for the movie series starring Mel Gibson and Danny Glover.
Lich (various): "Lich" is Old English ("lych") for 'corpse' or 'dead body'. (The German word for "dead body" is "Leiche"; they're related.) Also, a Lich is a kind of undead mage with no soul; a powerful magic user who chose to trade his soul for immortality as an undead. In Advanced Dungeons & Dragons, the Lich is an undead wizard that cannot be killed unless the object holding its soul is destroyed.
Li Grim (FFTA): This is short for Le Grimoire, which is a manual of black magic (for invoking spirits and demons).
Lobo (FF6): Spanish for 'wolf'.
Lunaris (FF6): Means, approximately, "from the moon".
Mafdet (FF10): Mafdet was an ancient Egyptian goddess who could provide protection against snakes, scorpions, and other dangerous animals.
Malboro (various): It is possible that this name comes from Marlboro Cigarettes, via his Bad Breath attack. But in FF6 NA, it's called Mad Oscar and Evil Oscar. The "Oscar" comes from Sesame Street's Oscar the Grouch, whom it vaguely resembles. Malboro/Marbolger(FF11) may be derived from Malebolge, one of the circles of Hell in Dante's Inferno thus hinting that such a monster is from this hellish locale.
Maelspike (FF10): Maelstrom + Spike.
Mandragora (FF10): Another name for the mandrake, a root said to kill whoever eats it, (some versions have it that this happens by the plant shrieking at the victim). Mandragora is also used in the creation of magical fetish dolls by those who believe in Wicca. The root is carved into a roughly manshaped appearance, and is then used in very much the same way as a voodoo doll.
Manticore (FF1): A Greek monster (originally an Indian one called Mantikhoras) with the head of a man, body of a lion, and tail of a scorpion. Mantikhoras means "Man-Eater". Also known as Androphagos.
Melusine (FF10): A French myth about a cursed woman named Melusine whose legs change into a serpent's tail every Saturday.
Metsanhenki (FF11): This twig-like monster from FF11 is a character of Finnish folklore whose name means 'spirit of the forest'.
Metsanneitsky (FF11): This twig-like monster from FF11 is a character Finnish folklore whose name means 'maiden of the forest'.
Midgar Zolom (various): See Terrato.
MindFlayer (FF1): He attacks with "Mind Blast", which sucks out your brain. I'm not sure which mythology he's from, but supposedly Mind Flayer is one of those truly evil beings who has no soul. Also known as "illithid". In D&D, illithids are known for their affinity for 'brain food' (in the literal sense), and their ability to suck out your brain instantly once they get all four of those tentacles wrapped around your skull. The game designers may have been making a nod to H.P. Lovecraft's popular Mythos of Cthulhu. Cthulhu was supposed to have the face of a squid, the wings of a dragon, and the body of a very large humanoid. More importantly Cthulhu is so horrible-looking that people are driven crazy by the mere sight of it.
Minotaur (various): From the Greek legend. The Cretan king Minos (meaning "from Crete", not "idiotic") supposedly had a soft spot... er, sexually... for white bulls. One of the gods sent him one to test him; after a bit of a mess, the end result was something having the head of a bull and the body of a man. "Minotaur" is Greek for "Minos's bull". Minos hired Daedalus (father of Icarus) to build the famous Labyrinth to imprison the Minotaur. However, eventually Theseus, aided by Ariadne's magical string, managed to foil the Labyrinth, kill the Minotaur, and come out unharmed. The other story is King Minos' wife, Pasiphae had dared compared her beauty to that of the goddess Aphrodite. The offended goddess then instilled Pasiphae with a love for one of her husband's prize bulls. The result of the union was the Minotaur. Minotaur's brother, Sacred, is mistranslated from Sekhmet. Sekhmet is a lion-headed goddess sent by Ra to punish mankind for its sins. Part of the triad that includes Bast (cat goddess) and Ra (the rather important sun god).
Mistodon (FF9): A cross between "mist" and "mastodon", a prehistoric creature that looked a bit like a woolly mammoth.
Mu (FF7): Mu was a mythical lost continent. However it was also believed to be inhabited by giant hermaphrodite lemming/rodent type creatures which match the description of the creature itself.
Mushussu (FF10): In Babylonian mythology, Mushussu was a three-headed dragon that served Babylonian goddess Tiamat.
Naga (FF4): A Naga is a long-tailed being from Indian legend (they show up in FF1 also). The HugeNaga from the Sealed Cave is Naga
Rajah originally; it means 'King Naga' and comes from Sanskrit.
Nastidon (FF6): Combination of "nasty" and "mastodon".
Nebiros (FF10): Nebiros is a half-insect, half-human demon.
Necrophobia (FF5): "Fear of death" in Latin.
Necrotaur (FF1): Latin for "death bull".
Nemesis (FF10): The Greek goddess of revenge or justice, but it's also a perfectly normal English word with a meaning similar to "archenemy".
Nidhogg (FF10): A serpent from Norse myth, which continually attempts to destroy Yggdrasil, the World Tree. Features prominently in Wagner's Ring Saga.
Ochu (various): The Ochu is another D&D rip-off, it looks identical to the game's Otyugh. (The latter are not vegetal, though.). It was probably named after the allergen attacks it uses. Ochu is an Igbo (African tribal language) for 'manslaughter' or 'murder'.
Olog-Hai (FF3): The Olog-Hai were specially bred trolls created by Sauron in Tolkien's LOTR that possessed no fear of sunlight unlike that or normal trolls. (Is this the same as Uruk-Hai?)
Ogopogo (FF4): Ogopogo is one of three legendary "pogo" creatures found in Canada. Logopogo can be found in a British Columbia lake. Manipogo can be found in Manitoba in the lake of the same name. Ogopogo can be found in Lake Ontario which is part of the U.S./Canada boarder. All three come from native legends and share the same description. All are described as long and slender and humped while traveling, basically the same as the Loch Ness Monster but not as well known (explains the palette swap). Also of note, when one (I think Logopogo, but I'm not sure) comes around birds are suppose to fly backwards. See Tidaliathan (below) for the Japanese version of this monster.
Omega, Omega Weapon (various): Omega is the last letter of the Greek alphabet. Hence these monsters being the hardest challenges in their respective games.
Ornitholestes (FF10): The name comes from a prehistoric dinosaur named Ornitholestes (which means 'bird robber' in Latin). It was a carnivore that walked on two long legs, and was about six and a half feet long.
Osteosaur (FF6): Greek for "bone lizard".
Over Mind (FF6): Probably inspired by Arthur C. Clarke's novel Childhood's End, in which there's a great being that transcends physical bodies. Eventually the human race is absorbed by the Overmind, and becomes one with it.
Ozma (FF9): Ozma is one of the names of the first SETI (Search for Extra-Terrestrial Intelligence) projects. Perhaps suggestive of Ozma's out-of-this-world appearance. Some people believe the name is based on Ozma from Frank L. Baum's The Wizard of Oz series, but there is no apparent similarity between the monster and the character.
Pandora (FF6, FF8): In Greek mythology, Pandora was given a box by the gods and told not to open it. She couldn't help herself, though, and she opened the box which released all the evils inside it out into the world (yet one good thing remained: hope).
Penance (FF10): Penance is a link to Sin; paying penance is atoning for the sins one has committed.
Phlegyas (FF10): In Greek myth, he's the son of Ares and Chryse, and ancestor of the Phlegyans, a people of Thessaly. He also happens to be Ixion's father. He's also the boatman who rows Dante and Virgil across the river Styx in Dante's Inferno.
Phobos, Triton, Nereid (FF5): Phobos means "fear"; it's also one of the moons of Mars. Triton is king of the seas and one of Neptune's moons, as is Nereid. Nereid was called "Nergade" in the PSX version.
Phunbaba (FF6): He is probably the very same 'Humbaba' from the Gilgamesh story. They're spelled the same way in Japanese; probably the translators had never heard of Humbaba and so they arbitrarily picked the spelling 'Phunbaba'. (See also Gilgamesh)
Primordite (FF6): Means "ancient", like the English word "primordial".
Prokaryote and Eukaryote (FF4): Prokaryotes are one-celled organisms from which modern complex beings sprang. A eukaryote is a multicelluar organism (like animals and plants). A prokaryotic cell doesn't have a nucleus, and a eukaryotic cell does. He also says that the reason they're on the moon is because when the lunar program was started, the astronauts were looking for simple organisms as evidence of life on it.
Prometheus (FF6): Though he's a rather insignificant enemy in FF6, he was pretty important in Greek mythology. Supposedly Prometheus created humans, and then stole fire from Mount Olympus in order to save them from freezing. But Zeus didn't like this and Prometheus was imprisoned. Later, though, Hercules frees him.
Pteryx (FF10): This is ancient Greek for "wing", hence its use in e.g. archaeopteryx.
Rakshasa (FF1): Quoting a Dungeons and Dragons trading card: "Rakshasas are a race of malevolent spirits encased in flesh that hunt and torment humanity. They savor the taste of human flesh and use illusions to get it. They have a limited form of ESP which allows them to disguise themselves as someone the human trusts." Rakshasi have been around longer than Dungeons and Dragons. A raksha, also known as a rakshasa, is an evil (usually) spirit in Hindu mythology. They usually appear as dogs, fat birds, or skeletons. They are the descendents of Rishi Kashyapa.
Ralvimahgo (FF9): Raluvimbha in Japanese. A rain-god of the Bavenda of Transvaal. All the destructive natural phenomena (earthquakes, floods, thunder, drought) as well as plagues are attributed to him.
Ralvurahva (FF9): Raluvlarva in Japanese. This is Raluvimbha + "larva" (see above).
Sahagin (various): Thinks this monster may have originated in Dungeons and Dragons (called Sahuagin there). They were based on the Deep Ones from the Cthulu Mythos.
Salamand Entite (FF12): "Salamand" is short for "salamander". Salamanders were mythical beats who were closely linked to the element of fire.
Sand Worm: Modeled after the tube monster from Return of the Jedi. Probably based after the Sand Worm creature from Frank Herbert's "Dune" series.
Sandragora (FF10): Sand + Mandragora.
Schizo (FF7): Schizo is the Latin word for split, since it is double headed, and its functions are split amongst its two heads. (Schizophrenia, for example, is to have a "split mind")
Scullion (FF6): Old English word which refers to a maid or servant who washes dishes and things. A nice word for one of Kefka's minions.
Shantak (FFX2): Shantak is a bird-like fiend from H.P Lovecraft's Cthulu mythos.
Simurgh (FF10): A giant bird of Persian myth.
Sinspawn Gui (FF10): The word Gui is a chinese word for "ghost" or "spirit". Also, the same Chinese glyph for Gui is used for the Japanese kanji meaning "oni" or "demon".
Skoll (FF10): Skoll was a wolf in Norse myth that pursued the Sun and Moon and would finally devour the celestial bodies at Ragnarok.
Sleipnir (various): Odin's eight-legged horse in Norse mythology. It was given to him by Loki, the Norse trickster god, as a joke. Loki, in order to distract the dwarf blast's horse, Svadilfari, a stallion of great strength, he changed into a mare. The offspring of this unusual coupling was Sleipnir. The name means 'glider' and Sleipnir can travel over sea and through the air and can outrun any other horse.
Sylvestre (FF11): 'Silvestre' is Spanish for wild, especially when referring to wild plants. Quite suiting for a Mandragora-type monster.
Snow (FF7): In Japan, the Snow Woman (or Yuki Onna) was a female spirit who lives in the cold climates. She is said to be unforgiving to wicked humans so she freezes them. Or tricks travelers by asking them to care for her baby when it's actually a block of ice.
Sphinx (FF1, FFMQ): Egyptian creature with a lion's body, a woman's head and shoulders, and eagle's wings. It would sit alongside a road and ask travelers that came by a riddle and eat anyone who got it wrong.
Stheno (FFMQ): Stheno was one of the Gorgons of Greek myth. The other two were Medusa (who's rather famous) and Euryale (who isn't). The Gorgons were terrifying dragon-like creatures who could turn people to stone just by looking at them.
Stratavis (FF10): Strato (sky) + Avis (bird).
Sylphi Entite (FF12): "Sylphi" comes from "sylph". The sylphs were immortal beings who acted as air elementals, according to Paracelsus.
Taharka (FF9): Takarka was an pharaoh in ancient Egypt. The Japanese name is Dahaka. This is "an ancient Persian demon of death, deceit, mendacity. He loves destroying life. Dahaka is usually depicted with three heads, while scorpions & lizards crawl all over his body.
Takouba (FFX2): The takouba is a straight, double-edged sword, with no hilt, used by the Tuareg people of Africa.
Tantarian (???): Dantalian in Japanese. In Christian lore, Dantalian is a lesser demon who could alter the thoughts of men, turning them from good to evil.
Taromaiti (FFX2): The name means "disrespect" or "opposition" in Old Persian. Taromaiti was a daughter of Angra Mainyu (Ahriman).
Tawrich (FFX2): This is a Daeva who is the personification of hunger.
Telstar (FF6): You fight Telstar in the imperial camp. Telstar was the name of the satellite which broadcast programs across the entire
world beginning in 1961.
Templar (FF6): The Knights Templar came into existence in 1119, and their symbol was a crown, with two crossed swords behind it. They were dedicated to the protection of those in the crusades. Their order was destroyed when King Philip the Fair had the Grand Master at the time executed for refusing to disclose the location of the Templar's treasuries and the identities of his members.
Th'uban (FF10): An Islamic demon that looks like a dragon. The word means "the snake" in Arabic.
Tiamat: In Akkadian mythology, Tiamat is the mother of the other gods. She has five heads (blue, red, black, green, and white). In some stories, she is enemy of Bahamut, king of the dragons. In FF8, Tiamat is indeed supposed to be related to Bahamut, and s/he looks very much like him in that game. In Babylonian mythology, Tiamat co-created the world with her husband, Apsu. Later on, Ea (the god of wisdom) slew Apsu; and his son, Marduk, challenged Tiamat. Marduk eventually slays Tiamat. Tiamat is also the Sumerian name for Leviathin and Absu is also known as Behemoth and even Cthulhu sometimes. Tiamat usually has five heads but can have anywhere from three to six. Tiamat (and Bahamut) are major characters in Dungeons & Dragons (the Evil and Good Gods of the Dragons, respectively). Note, in legend Tiamat originally had a human form but took a Dragon's in her rage after Apsu's killing.
Tidaliathan (FF4): This was translated as Ogopogo in the U.S. version. It's an amalgamation of "tidal" and "Leviathan".
Tindalos (FFX2): This monster is based off the Hounds of Tindalos from the Lovecraft mythos that exist in an alternate realm where evolution has not started. These beasts are fierce towards and time or dimensional travellers.
Titania (FFTA): The queen of the fairies in European legends. Appeared in Shakespeare's play, A Midsummer Night's Dream.
Tomb Thumb (FF6): Not really mythological, but the name comes from "General" Tom Thumb, who was only about three feet tall. He joined P. T. Barnum's exhibition in 1842 and went on tour in the U.S. and Europe from 1844 to 1847. The "Tomb" part is of course a pun. General Tom Thumb's name is takn from a folktale in which a poor couple wish for a son, even if he's only as tall as a thumb - and their wish is granted.
Ultima Weapon (various): See Misc.
Undine Entite (FF12): "Undin" most likely comes from "undine", which was a type of female water sprite in Teutonic folklore.
Uroburos (FF6): Ouroboros is the depiction of a snake eating its own tail, first seen in Ancient Egypt. It is also found in many other mythoi, including Norse mythology, Hinduism and Gnosticism. It symbolizes the cyclical nature of the universe, how life comes from and depends on death and vice versa. Some incarnations of ouroboros depict the snake as half black and half white, which, not unlike a yin yang, symbolize the necessity and interdependence of good and evil in the universe.
Valaha (FF10): Valaha may be a misspelling of Varaha, the boar incarnation of the Hindu god, Vishnu.
Valia Pira (FF9): This is very possibly a mistransliteration of "Barrier Pillar".
Varuna (FF10): Veruna (the fiend in the Omega Ruins that looks like Diablos) is the supreme god in the pre-Vedic Indian religion.
Vidatu (FF10): Asto Vidatu was the Persian and Zorastrian demon of death.
Voivre (FF10): A French dragon goddess (the name comes from ancient Gaulic for "snake"). She supposedly lives as a white snake under elder trees; she acts as guardian of treasures and guide to the Otherworld.
Vysage (FF8): The English word "visage", meaning face.
Warg (FF1): Wargs were intellgent wolf-like creatures in Tolkien's LOTR. Also, the word Warg likely comes from the Old Norse "vargr" meaning 'wolf' anf 'outlaw'.
Wendigo (FF8): In Hindu mythology, the Wendigo is an evil spirit that can possesses humans, and can thus transform humans into monsters. In Native American myth, the Wendigo is an evil spirit that flies down from the sky and attacks people that do evil deeds; it pulls the person up by the hair and then throws them into the sky. In the American midwest, it was usually portrayed as a giant man clothed in white with a star on its forehead. If you saw one, one of your family members would die. Certain Native American groups still claim to see this monster.
Whelk (FF6): A whelk is an extremely large sea snail. It can grow to a size of 16 inches.
Wingraptor (FF5): A raptor is a bird of prey, and there's a dinosaur called "velociraptor".
Wolfmeister (FF7): This is a mangling of Wolframiter (the name given in Japan). Wolframite is a crystalline ore composed of huebnerite and ferberite.
WrexSoul (FF6): It is a mispelling of AlexSoul from the Japanese version of FF6, which is obviously a combination of Alex(ander) and Soul; it is the monster who provides the Esper Alexander.
Wyvern (FF4, FF6): The Wyvern guarded one of the really powerful weapons in the Lunar Subterran of FF4. A Wyvern is a breed of monster; half dragon and half eagle. He's called Dark Bahamut in the import and also appears in FF6 on the Lethe River.
Xiphos (FF10): Greek for "sword". Note that Espada is a palette swap of it.
Yowie (FF10): The Yowie-Whowie, a creature of Australian legend; described as a dragon. It's like a lizard with a armored body & six legs. It lairs in the cool shadows of caves during the day, & hunts at night. Ideal prey is a human, which it can gulp down with about two bites.
Zarich (FFX-2): This is a Daeva who is the personification of aging.
Ziggurat Gigas (FF5): A ziggurat is a kind of pyramid-like tower with concentric steps; it's also from Mesopotamian culture, built by followers of Zoroaster. (The PSX version had this as an unimaginative "Ultragigas"). A Ziggurat is a tower made by man to prove that they are powerfull, like gods(in some cases more powerfull then gods) and often put fear into the peasents and enemies. Allegedly, God grew angry at this and sent angels down to destroy them(or something along those lines) The Mayan and Aztec temples where often regarded as ziggurats.
Zu/Zuu (various): Zu was a demonic tempest bird from Mesopotamian mythology. It lived in the underworld and stole the tablets of fate from Enlil, a major Mesopotamian deity. Zu was defeated by a god, Marduk, or in some versions, was overcome by Enlil's son Ninurta.
Zurvan (FFX2): A god of space and time in Persian mythos. Apparently, this god also begat both Ahriman and the Ahura Mazda.