Crawlers also don't take fall damage and will survive a drop from nearly any height. They can also scale up walls and fit into small crawl spaces which opens up numerous alternate routes to get around traps. they move a little bit faster and have the same amount of health but attack twice as fast with a double swipe making it easy for them to take out stronger humans such as bodyguards and riot troopers.
Overlords: The first mutation you come across in chapter one and by far one of the most useful, when a zombie is changed into an overlord their torso falls to the ground at their feet in a pile of gore leaving behind only their heads, spines, and arms to command the horde.Whether it's a light slasher or a bulky hulk, mutations are essential to success - especially since they can synergize into combos. Mutations are a special feature of zombies, allowing them to develop new abilities and adapt to the challenges of a given map.
Not that it matters to the unfortunate humans getting ripped and torn. RIP AND TEAR is what this hulking monstrosity would scream if its vocal chords weren't completely rotten.