For This, play as Guardian, make sure you get the Bonk Hammer Perk, you'll get it via Level up as you progress via Canyons and then through Oasis. Once you get it and if RNG is on your side and you get Diggy Mole as your boss at the end of the Level, then get his health down to a quater, and then keep bonking him with your bonk hammer (Melee attack) be careful not to accidently headbonk him.