Leonard Ornstein is an American actor and retired professional wrestler, best known under the ring name "Wildman" Jack Armstrong from 1960s to early 1990s. Best known working for Herb Abrams's Universal Wrestling Federation and World Wide Wrestling Federation. His feud with Jay Strongbow Jr. in the mid-1980s resulted in "some of the bloodiest encounters ever seen in California".
Armstrong made his professional wrestling debut in 1963.
In 1968, he made his debut for the WWWF (World Wide Wrestling Federation) in New York City as Lenny Solomon. He feuded with The Sicilians Lou Albano and Tony Altomare. In 1969, he left the WWWF.
Throughout the majority of his career. He worked in Japan, AWA, Los Angeles, Georgia, and various territories during the 1970s. From 1983 to 1988, Armstrong worked for the WWF as a preliminary wrestler. He only worked in Los Angeles when the WWF came to town. Armstrong appeared in three films - Grunt! The Wrestling Movie (1985), Bad Guys (1986) and Body Slam (1986) - during this period.
In 1990, Armstrong worked for the brand new promotion Universal Wrestling Federation (UWF).
Armstrong became the first and only champion by defeating Mando Guerrero at the final UWF show in 1994.