LOS ANGELES - Actor Len Lesser, who starred on "Seinfeld" as Jerry's eccentric, shoplifting Uncle Leo, died on Wednesday after a battle with cancer. He was 88.

A friend told Reuters Lesser was admitted to a rehabilitation center near his home in the city of Burbank several weeks ago, and died peacefully after breakfast.

Although the television and movie veteran appeared in just 15 episodes of "Seinfeld," his idiosyncratic character was a key ingredient in the offbeat tone of the 1990s sitcom.

His traits included a boisterous "Jerry! Hello!!" whenever he saw his comedian nephew, played by Seinfeld. His last name was never revealed, but everyone knew him as Uncle Leo.

In one episode, Uncle Leo accused a chef of being anti-Semitic because his hamburger was undercooked.

Lesser's baldness and sharp visage were used to comic effect throughout the show. Jerry once labeled him an "Adonis," who should be swinging. But he reversed course later in the same episode, declaring: "If there's a woman that can take your presence for more than ten consecutive seconds, you should hang on to her like grim death. Which is not far off, by the way."

New York-born Lesser's TV career began in the 1950s and included roles opposite Steve McQueen in "Papillon" and Clint Eastwood in "Kelly's Heroes" and "The Outlaw Josey Wales."

In his later years Lesser had a recurring role on "Everybody Loves Raymond" as a crony of star Ray Romano's father, played by Peter Boyle. His last appearance was as a neighbor in a 2009 episode of the TV show "Castle."