Paul Jeffrey "P. J." Byrne (born December 15, 1974) is an American film and television actor. Byrne is best known for his roles as Nicky "Rugrat" Koskoff in the Martin Scorsese film The Wolf of Wall Street and Bolin on Nickelodeon's animated series The Legend of Korra. He also starred as lawyer Scott Leavitt on the HBO series Vinyl.