The hollow spends the fight flying around the room diagonally, bouncing off of walls. It usually spawns in two segments, but can rarely appear as one long chain of segments. Upon killing a segment in the middle of the body, that section will split into two entities which will both continue flying. Like Larry Jr. they occasionally spawn poop.
The Hollow does not shoot, and does not deviate from its diagonal trajectory; its only attack is contact damage with the player.
- Gold: Chance for each segment to drop a coin on death.
- Green: Chance for each segment to spawn a charger on death. Occasionally stops movement to shoot 3 bullets at wherever it is facing.
- Black: Spawns a Boom Fly when killed.
- Sometimes this boss will get stuck on the wall