Note:
- I've counted mainly monster families except in cases where specific models have undergone significant changes to their skeletons and textures.
- I'm sure I missed some. I purposefully excluded a few like the Garlean generals, for example.
- Some may be duplicates.
- I don't have strategy guides for FFXIII-2 and Lightning Returns, so I don't know if anything was taken from there (beyond Ultros and Typhon).
- Some didn't really fit into any category. Elementals and Giants draw from FFXI, but also have several fairly unique models in FFXIV, for example.
Sources:
http://ffxiv.gamerescape.com/wiki/Category:Bestiary
and the bestiaries of various strategy guides
FFXIV 1.0 (60): Ghost, Wight, Aldgoat, Antelope, Bat, Boar, Buffalo, Mole, Rodent, Sheep, Wolf, Dodo, Hippogryph, Mammet, Vanguard, Eft, Drake, Peiste, Puk, Cactuar, Funguar, Landtrap, Morbol, Treant, Coblyn, Dullahan, Golem, Spriggan, Amaljaa, Ixal, Moogle, Sylph, Antling, Beetle, Chigoe, Firefly, Swarm, Yarzon, Ahriman, Bomb, Cyclops, Gnat, Ogre, Snurble, Plasmoid, Clam, Gigantoad, Jellyfish, Megalocrab, Slug, Garuda, Ifrit, Titan, Chimera, Batraal, Coeurl, Kobold, Flan (pudding), Magitek Dreadnaught, Orobon
FFXIV 2.0 - Monsters (26): Bear, Behemoth, Zu, Beast tribe Machinae, Death Claw, Sea dragon, Wyrm, Gremlin, Sahagin, Diremite , Succubus, Elbst, Beacon, Magic pot, Hecteyes, Baalzephon, White Magestone, Harpeia, Floating head, Megalotragus, Wyvern, Facer, Ziz, Magitek Reaper, Magitek Colossus,
FFXIV 2.0 – Bosses (40): Ultima, Gobmachine, Siren, Demon Wall, Leviathan, Ramuh, Shiva, Ash, Catoblepas, Arioch, Giruveganaus, Sasquatch, Kraken, Cuca Fera, Captain Madison (Redux), Wandil, Yeti, Vicegerent To The Warden, Anchag, Boogyman, Ferdiad, Einhander, Magitek Gunship, Midgardsormr, Gilgamesh, Enkidu, Odin, Phlegethon, Scylla, Glasya Labolas, Amon, Xande, Twintania, Nael Deus Darnus, Angra Mainyu, Cerberus, Cloud Of Darkness, Phoenix, Bahamut, Hydra
FFXI (38): Manticore, Opo-opo, Apkallu, Colibri, Vulture, Adamantoise, Dragonfly, Ogrefly, Raptor, Anantaboga, Goobbue, Mandragora, Ochu, Sapling, Goblin, Mamool Ja, Qiqirn, Tonberry, Giant hornet, Sandworm, Wamoura, Demon, Imp, Soulfalyer, Taurus, Vodoriga, Crab, Pugil, Uragnite, Scorpion, Lamia, Fenrir, Wivre, Manxome Molaa Ja Ja, Atomos, Ooze, Bhoots
FFXIII (7): Clockwork Warrior, Clockwork Dreadnaught, Aspect of Chaos, Behemoth, Anubys, Ultros, Typhon
FFXII (10): Croc, Serpent, Mirrorknight, Clockwork Bug, Mantis, Aevis, Dragon - ring wyrm, Tyrant, Defense node, Statue
FFVIII (1): Diabolos
Other (4): Elementals, Giant, Two-headed Dragon/Five-headed Dragon, Enemy humanoid (Ascian, Belahdian Knight, Mummy/Zombie/Fomor)