Here is the full list of all 9 Jabroni Brawl: Episode 3 achievements.
Met postal.
Fired a gun.
Found and possessed a monster.
Found and possessed the third possession.
Unlocked a new secondary fire for the Hand Grenade, a cluster grenade!
It's actually still the same.
Killed 53,593 scientists.
Won a Battle Royale match by doing absolutely nothing.
Destroyed 100 mines.