Void

Void is the final boss of the game, spawning at wave 38. It has 500,000 health, and kills the player upon touching them.

Trivia

 * It has the most health of any zombie, at 500,000, however the health depends in the players.
 * Unlike the Tower Battles Void, this one has a 'Strike' ability that kills anything in front of it. A bunch of circles colored yellow will appear in front of it, and slowly it will turn red. Once it's red, anything near it will die.

* =not 100% sure