Each map in zombie mode has its own boss. Most of the bosses have identical behaviors. All bosses take only 20% damage from a player and the maximum damage that a boss can take is 100%. Clamp of maximum damage is before percentage reduction. All bosses except for the Witch have 300 hit points (HP). The Witch has 130 HP.
All Bosses, like other Zombies, chase the player. The Clown boss has two behavioral patterns:
- Normal - Similar to normal zombies
- Rage - Boss will sprint after the player. Its speed is triple at this stage and damage is doubled.
The angry phase lasts 1.2 seconds to transit to normal phase. The normal phase takes 8 seconds.
The Witch boss is unique in that she can fly and has a ranged attack. If a player gets too close, the Witch will retreat. Once she retreats for some distance, she will continue to go after the player.