Butt Zombie

Butt Zombie is a Boneyard undead enemy that burrows underground and resurfaces on any open tile of its choosing, bypassing all obstacles. On arrival it delivers separate melee attacks against every adjacent unit in sequence rather than one area hit. When damaged it flips upside down, and a second hit while inverted triggers a fart that knocks back all surrounding units and inflicts Poison 4. It also farts automatically if it starts a turn upside-down. Moving while inverted restores it to normal. It leaves no corpse on defeat.