Jonathan Anthony Wisniski (born September 20, 1951) is an American professional wrestler, better known as Greg "The Hammer" Valentine. He is the son of wrestler Johnny Valentine. Over five decades, Valentine held more than 40 championships, including the NWA United States Heavyweight Championship, WWF Intercontinental Heavyweight Championship, NWA World Tag Team Championship, and WWF World Tag Team Championship. An alumnus of Mid-Atlantic Championship Wrestling, the World Wrestling Federation and World Championship Wrestling, he was inducted into the WWE Hall of Fame Class of 2004 and the Professional Wrestling Hall of Fame in 2016.
