
Vomiting zombies can freeze and vomit but it does not cause damage.They will then die for no apparent reason after some seconds. When there are a lot of players in a building, zombies that are following players will rarely become seemingly invincible and will continue to chase you down even after being crit-hit several times.The same can rarely happen to bosses. Bloats may automatically explode causing damage to nearby players. Some zombies sometimes become invulnerable for a while, after some time they freeze and die.Spiders are known for this and cause a problem to less experienced players. Some unique zombies freeze for a while and then return to their target.Sometimes during an Outpost Attack leapers can spawn behind you and instantly hit you killing you in 1 clear strike.

During missions with a kill zombies objective, the kill counter resets itself back to a previous kill count, this happens more often when playing with several players and can even force you to kill three times the amount required.
