Some dungeon ideas, share yours!

[Necromunkey]

I want to enter a dungeon which is actually the mouth of a giant pudding! And we attack it from the inside! It's so squishy and purple!

...Ok, that's lame.

I kinda like this idea, It reminds me of the dungeon\level inside the whale in Kingdom Hearts. Final boss could be fighting the slime's tonsils or uvula (if they have them, I'm not a slime biologist), or perhaps something at the other end of slime anatomy =P