Bat King

Bat King is a demon found in Iris and the Giant.

"The four demons around this bat are untouchable. It also lets my enemies attack twice!"

Location
In Path of the Giant, Bat Kings appear on Floors 11W & 17, and additionally on Floors 5B & 14 on Nightmare difficulty.

In Path of the Ferryman, they appear on Floor 24, and additionally on Floor 3 on Nightmare difficulty.

Strategy
Bat Kings combine the abilities of the Bat and Mouse demons, i.e. the demons on all four sides of it will be invulnerable, and every demon will also be able to attack twice per turn. The Bat King will appear with 2 armor.