Iron Age Monsters

[FATDRAGONGAMES]

Celtic and Viking mythos is also relevant to the Iron Age, so plenty to go at there - giants, undead, trolls, faerie etc.

Ditto, this would be my pick as well.

 

[Tonguez]

The Roman world was filled with ghosts and spirits, which is probably why they didn't have too many physical monsters unless you include the various exotic 'animals'. Romans did have salamanders, unicorns, sphinx, chimaera and serpentine dragons

and there is a Roman mosaic showing pygmies riding crested crocodiles and fighting long legged hippos

 

[gamerprinter]

Iron Age - you're talking the time of Tuatha De Danann in Ireland, Beowulf, Sigfried, and the Norse Sagas if you stick to northern Europe alone. So we're talking dragons, worms (more like Linnorn), giants, ogres, hags, trolls, fey, ghosts, ghouls, early vampires, lycanthropes, merfolk, selkies - really most of the traditional D&D monsters.

Not Bronze Age beasts like minotaur, sphinx, centaur, etc - Ancient Greek. Not the iconic D&D bugbear, illithid, carrion crawler (Gygax inventions). Not much on the demon, devil, angel which is really more modern (Christian Europe) or remnants of ancient gods. But most everything else.