A nipple, that when squeezed, discharges a puss like substance.
In Thailand, they believe the discharge is rich in vitamin E, hence the name being Rich-e's Nipple.
Jared: "Wurt? Wurt the hell do you want this time Bill?"
Bill: "That guy with his top off has totally got a Riches Nipple!"
Jared: "Dude. That's not a Riches Nipple. He's not even squeezing it. Just means the dude don't bath."