Origin: Duke Nukem 3D

Duke's a regular treasure trove of memes, but perhaps one of his most famous is "I've got balls of steel," which was the prime focus in YouTube sensation Ventrilo Harassment, where the sound bite was repeated incessantly to innocent members of the Vent server, who found themselves irrationally angry when dealing with the lewd sound clips, thus spawning one of the most guffaw-inducing memes ever.