Darth Vader's penis was Darth Vader's penis, Duh. It was frequently a victim of the Force choke, although rarely in public. After the fall of the Jedi Order, it featured quite prominently in the Rise of the Sith. It is used in a similar fashion to the lightsaber, holstered at the hip, although most of its abilities can be negated with a cold shower. Power levels have been shown to rise in the presence of specific materials. His penis was never replaced with a functioning robot dick and is now a series of tubes allowing him to pee. In it's place is now a pez dispenser.