Bubble Monster

This is living Bubbubbub.

hp 54

AC 10 HD 10 +10 to attack -4 to initiative

Absorb: 1d6 damage, reflex save DC 10 or get absorbed inside of the monster. Opposed STR (it has +8) to get out. Run out of breath in 5 rounds.

Electricity stuns it for 1d4 rounds.

It will fill up most of the room it's in, but it's actually fairly slow-moving. PCs can shimmy past it along the edges of the room by making a DEX check DC 12. Failure means they stop moving through the room for the round, and if the Bubble Monster hasn't taken an action in the round, they may attack.