The Zombie Parts system in Dead Island 2 is an incredibly morbid mechanic with some really interesting concepts. Basically, at a certain point in the game, players will unlock the ability to use different mutations in different zombies to create specific Autophage Perks and Skills for weapons. To do this, you'll need to collect all sorts of anatomical nightmares from Oversized Arm Bones to Electrified Brains, Mutated Hearts, and even Infected Flesh.