The superhero alter-ego of the character Cat in the Newgrounds Flash series Retarded Animal Babies Episode 4: Stupor Heroes, animated by David C. Lovelace. He has the 'power to penetrate mighty fortresses', though he 'prefers shaved fortresses.' See also: Infinity Lad, Bruce Willis-Man,Satan Man, the Fucking Fucker, and the Triple-D Triplets.
Cat: I'm the Purple Penis! I penetrate mighty fortresses, and sometimes hairy ones!
Oh yes, a purple penis is a penis that a dwarf leprechaun has. He willchase you down and whack you in the face with his dick. He will jizz cum all over you and with his Cheeto dust pubic hairs.