Complex sentence: Leonard King "Len" Lesser (born December 3,1922) is an American actor best known for his role as Uncle Leo on "Seinfeld" after having joined the cast during the second season.
Split into simpler sentences: Leonard King "Len" Lesser (born December 3,1922) is an American actor. He is best known for his recurring role as Uncle Leo on "Seinfeld", which began during the show's second season.