Enforcer

How to unlock: The Enforcer is unlocked by killing the Magma Worm, Wandering Vagrant, and Colossus.

The Enforcer is a slow, but powerful character. Batting away enemies with Shield Slam guarantees you will keep enemies at a safe range. Make sure to use Protect and Serve against walls to prevent enemies from flanking you.

In the ending cutscene, the enforcer-specific text says: "'And so he left, mutated beyond recognition."

Tactics

 * Surviving as Enforcer is difficult due to your low mobility. Having such an unforgiving skillset, you want items that will "give you a second chance" in combat. Items like boxing gloves, permafrost, and warbanner will provide high utility evading or delaying enemies. Your healing items should be Mysterious Vial, Med Kit, and Leeching Seed. Essential items for surviving brawls with enemies are the Guardian's Heart and Foreign Fruits.
 * Positioning for Protect and Serve is crucial to success. Being the most stationary character, items that are most effective on the Enforcer are ones that help you take out large hordes of enemies at a time.The Will-o-the-Wisp, Brilliant Behemoth, Gasoline, and other "damage on-kill" items will help you make short work of the waves.
 * Shield slam will knock enemies, regardless of their orientation, towards the direction the Enforcer is facing. The hitbox for Shield bash also extends slightly behind the Enforcer as well; however, hitting an enemy at the edge of Shield Slam's range if they are behind the Enforcer will send them backwards.
 * Protect and Serve can kill you just as easily as it could save your life. It is important to stagger your Shield Slam and Crowd Control abilities if you get into  a bind. Be careful of enemies like the Rock Golems, you want them close to block damage with your shield, but if they get too close, their long reach can still hit you even from the front.