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 will chase 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.