Jonah Falcon's penis is 9.5 inches flaccid, 13.5 inches erect. Tense your
forearm. Now wrap your hand around the middle of the muscle. That is the girth of Falcon's erection.
Falcon asked that if his mother was to be interviewed, his penis not be mentioned. "I'm pretty sure she knows about it, but it's not a topic for a mother."
Asked about his childhood, [his mother] interrupts. "I know the reason you're calling. Look, it's genetic. He was
born like that, and he was always big for his age. But it's not his big penis, it's
society's need to fixate on it. We're in a world where men see their manhood in their penises."
Rolling Stone article
Article has a link to his site with... pictures.