Pit fiend

Pit Fiend
A pit fiend often wraps its wings around itself like a grotesque cloak, and appears wreathed in flames.

A pit fiend is 12 feet tall and weighs about 800 pounds.

Combat

Pit fiends are wily and resourceful fighters, using invisibility to gain the upper hand and biting at foes seemingly able to see them. They don’t hesitate to blanket an area with fireballs, and can call down the wrath of an inferno with meteor swarm.