The Amazing Head

 is the boos of the second part of Mandatory Fun Zone.

Attacks
The headless magician attacks by launching projectiles, one at at time. They are fairly easy to dodge, with the primary problem being the zombies that attempt to swarm your hero. Another is that whenever you get close, the magician will teleport away, disappearing in a puff of purple smoke.

Strategies
The strategy here is simple: Follow him and hack away. The destination of the magician is marked on the map as purple smoke, allowing you to easily identify where he will appear. Melee characters are surprisingly effective at beating him down.