The Least Plausible Word in "Dungeons And Dragons"

Dungeon:

A twisty, constricted subterranean maze.

Food is hard to find.
The monsters get harder as you go down levels from the surface.
The toughest, hardest monster in the dungeon is ...

The dragon:

A large flying meat-eating creature.
Pretty formidable in combat ... unless attacked from the back with no way to turn around.

So shouldn't it be "Dungeons vs. Dragons"?