Bear

Bear is a demon found in Iris and the Giant.

"These little creatures seem invincible... For once, I'd like to look on the bright side."

Location
The Bear can be found on Floors 9 & 16 Path of the Ferryman, and also Floor 5 on Nightmare difficulty.

Strategy
Attacking a Bear will flip its head upside down, and back if attacked again. They are unable to attack you while their heads are upside down. To defeat them you need to end your turn with all of their heads upside down; every Bear on the floor, even those off screen.

Alternatively, they can still be defeated individually with instakill cards (Dagger and Boulder).