Right then, we can have a mini-competition for folks to come up with quirky monsters to attach to aforesaid names - with quirks to make players confused...(rubs hands together fiendishly...)
Another possibility is that some of them could be used as alternate or local names for pre-existing D&D monsters.
Hmmm. . . This game could be fun. Here's what I've got:
Amphithere - Couatl (or at least a variant type of one that looks more like a dragon instead of a snake)
I could see an anthropomorphic animal race (such as Leonins, Lizardfolk, or awakened Girallons) calling humans "Glabrous Apes"
A Mesmeric Beetle as a distant relative of the Flail Snail (with the Scintillating Shell as an Exoskeleton)
Catobleghasts are obviously just Ghast versions of Catoblepases (Katoblepones?)
A Colorless Dragon is just a Chromatic Dragon that was bathed in bleach (possibly doing Force Damage with its breath weapon).
Stone Eagle is just a mistranslation/miscommunication for the name "Roc".
Face of Rays is another name for a Beholder
A Giant Giant is what you call a Goliath that takes levels in Rune Knight
Gigantopithecus is just a Giant Ape
The
GOAT OF CHAOS is just the childhood playmate of
Kezef the Chaos Hound (Or, alternatively, the name for the 3rd Form of the goat figurines of wondrous power.)
A Giant Kobold is just what you call a Dragonborn (one with a tail, that is).
A Lady of the Oaks is just a Dryad (possibly cousins with the Lady of the Lake).
A Lumbering Calamity is what you call an
Adventuring Party
Mermaster is what you call a Magic: the Gathering player that focuses on Merfolk decks (or, rather,
what the call themselves).
A Double Ogre is what a bard likes to call an Ettin when using Vicious Mockery (who then proceeds to double over in laughter).
An Orc-Bat is what is depicted in
this image from Volo's Guide to Monsters.
A Rust Man is what any Warforged Adventurer becomes after having an unfortunate encounter with a Rust Monster.
A Shrinker is just a Duergar Mind Master (due to their psychic powers letting them become Tiny instead of Large).
An Ancient Troll is the Alter-Ego for the first bard to ever join an internet forum. (Summoning
@Snarf Zagyg.)
This is the Ultrakraken.
And a Zombie Wizard is a Reborn Wizard (extra points if it's a Necromancer).