Zip This Up - Shoot an enemy in a sensitive spot.

Ow My Balls! - Do your first nutshot AND testicle assault.

(Requires both melee and gunshots to the groin)

"See the Future" DLC: The Nutcracker - Score 25 groin shots, or see another Hero do so.

"Doc Ketchum's Murder Service" DLC: Just Like Old Times - Dispatch the professor with a shot to the groin.

Base Game: The Nutcracker - Sweet! - Incapacitate an enemy, then shoot them in the testicles

"Target Fuhrer" DLC: Albert Hall - Kill the Dictator with a testicle shot

Base Game: Die Nussknacker Sweet! - Get a testicle shot with a rifle from a distance of 100 meters or more.

"Wolf Mountain" DLC: Das Familienjuwel - Kill Hitler with a testicle shot.

Base game: Charlie's Challenge - Get a testicle-shot from over 100m away

"Hunt the Grey Wolf" DLC: Herr Charles - Kill the officer at the meeting with a testicle shot.

"Stranglehold Map Pack" DLC: Testikill - In multiplayer, kill an opponent with a precision aim crotch shot.

Poor Sportsmanship - Hit 30 enemies in the groin during tactical time dilation.

(Technically can probably be done with melee too, but including it here anyway)