Regurgitator

The regurgitator is a boss zombie found first in the first mission. It attacks by either swinging its massive trunk-like arms at the player or spitting acidic bile and fetid worms (hence the name regurgitator). When defeated, it drops a strongbox (only one regardless of number) and releases a massive swarm of worms. When the regurgitator is at low health, it's recommended to reload your ammo so you can deal with the worms. Avoid getting too close (those arms are much, much tougher than the worms). This boss is resistant to acid (?) but is pretty much weak against anything else.