Stephen Furst, whose early role as the hapless, lovable fraternity pledge Flounder in the hit 1978 comedy “National Lampoon’s Animal House” earned him lasting recognition, died early Friday at his home in Moorpark, Calif. He was 63.

The cause was probably congestive heart failure brought on by complications of diabetes, his son Nathan said.

The chubby naïf Kent Dorfman, nicknamed Flounder, was one of his earliest professional roles, one that he remained proud of throughout his career, and returned to for the short-lived television series “Delta House.”

The movie, set in the early 1960s, is about an unruly fraternity that the college administration wants to shut down. In her review in The New York Times, Janet Maslin said, “Stephen Furst does some very successful scene-stealing as the house blimp.”