@ralpharama I was going to suggest lifting from #NetHack but I don't know how they approach the legalities of e.g. https://nethackwiki.com/wiki/Gelatinous_cube
#Folklore should be safe: https://en.wikipedia.org/wiki/List_of_legendary_creatures_by_type
@GardenOfForkingPaths thanks! I have sifted an old dnd list for the most commonly known, and I would say public domain, creatures like orcs, ghosts, ghasts, spiders etc... I'll work with that for now - the folklore page is a good one!