The brother of the actor Michael Lerner, Ken Lerner made his onscreen debut in a 1977 episode of the sisterly-roommates sitcom "Laverne & Shirley. " After parlaying his brief role as a motorcycle-gang member in the bawdy comedy "Gas Pump Girls" into a recurring role on the long-running retro comedy series "Happy Days," the actor made subsequent TV appearances on such popular shows as "The A-Team" and the revamped "The Twilight Zone." With small roles in films such as the military-experiment adventure "Project X" and the futuristic Arnold Schwarzenegger-starring thriller "The Running Man," Lerner established himself as a character actor dependable for playing luckless nerds and sycophantic underlings. He brought his persona to a recurring role as the oddball attorney Jonathan Saunders on the acclaimed medical drama "Chicago Hope" before appearing as the ill-fated Principal Flutie on the opening episodes of the celebrated fantasy saga "Buffy the Vampire Slayer." Working almost exclusively in television since the '90s, Lerner has guest appeared on such other popular series as "Weeds," "NYPD Blue," and "Two and a Half Men."