The Dungeon With The Crabs is considered a bit of a joke by people who don’t think through the implications. It’s literally just crabs. They chase you in a circle around an island at slightly greater than an average walking speed.
”No big deal!”, says the average person. “I can walk slightly faster than a bunch of crabs!”
It takes twelve miles to cross the island in its current configuration. Anyone who can walk twelve miles can usually escape the dungeon, no big deal.
But.