I have noticed that this isn't that popular of a punch among the good southpaws but if i were to say someone used it and had a good one it would be winky wright or kassim ouma. Zab, Tarver, Sharmba, Byrd and Pac-Man, hardly uses it. However they do tend to have better jabs(than right handed fighters) and right uppercuts.

judah actaully likes to do a running leaping right hook when he has his man hurt

I have noticed that this isn't that popular of a punch among the good southpaws but if i were to say someone used it and had a good one it would be winky wright or kassim ouma. Zab, Tarver, Sharmba, Byrd and Pac-Man, hardly uses it. However they do tend to have better jabs(than right handed fighters) and right uppercuts.
Best one I ever saw was the one Morales kept landing on Pacquiao.