***D&D has a long history of pretty darn silly monsters. Some of them, like the rust monster and the owlbear, exist solely because Gary Gygax has a weird plastic toy that was about the right scale for the miniatures. Others evolved from literature, like the Illithid's origins as medium-sized Cthulu monsters. Some came from the tropes of the game, such as the mimic being a trapped chest plus or the gelatinous cube being an invisible menace in the halls of a dungeon that the unwary might walk into. Really, none of them are any less silly than a lion with the wings of an eagle and face of a human. Or a lion with a serpent for tail and second goat head. Or a winged lion with scorpion tail. (Geez, what is with lions anyway?) But Mythological creatures have slipped into the cultural zeitgeist, so their inherent laughability goes more-or-less unnoticed, in much the same way a group of seasoned D&D players will panic at the sight of a floating beach ball covered in eyestalks whose name is a cheeky reference to the adage "beauty is in the eye of the beholder", despite the fact they're fighting an improbably floating ball covered in eye-tenna.It's interesting to look at some of the more recent D&D Monster Manuals, specifically the Monster Vault, that really seems to focus on monsters that are the Intellectual Property of WotC; those are the Name monsters for experienced players, but they are also the monsters that will be the most silly for inexperienced and uninitiated players. I remember back in jr. high when I first started playing AD&D, it was the Greek and Egyptian monsters that really begged to be used, while I ignored the tanar'ri and baatezu with a "wha...", chuckled at the tarrasque, and dismissed the Mind Flayer as "some dude with an octopus for a head."
