An extraordinarily attractive, merman-esque version of a stud. usually to the point that when a studmuffler walks into the room, all previously bigheaded 'studs' become invisible to the eyes of any surrounding females. Usually plays water polo.
"Sarah, have you seen John? He's like a merman-lifeguard-waterpolo-god... What a studmuffler, I can't take my eyes off of him."
by Baneeee May 13, 2013