happens when you jerk off with shampoo and the chemicals react with your skin. the skin on your penis proceeds to dry up and become scaly and iguana-like.
guy 1: i am never jerking off with shampoo ever again
guy 2: do what happened? (guy 1 shows guy two his penis) gross! your dick looks like a damn iguana
guy 1: (to himself) hmmm, iguana dick. i'm gonna put this on urban dictionary.