TabletopThe Dumbest Dungeons & Dragons Monsters Ever (And How To Use Them)Tabletop - RSS 2.0
First published in: Monster Manual II (1983)
It's a stinky cow from the Nine Hells. This creature is irredeemable.
How to use it: Don't.
To be fair, the list doesn't stop there. Sound off in the comments with your personal dumbest D&D monsters.