According to TMZ, 63-year-old actor Ron Palillo—best known for his role as Arnold Horshack in the 70s' classroom sitcom Welcome Back, Kotter—passed away in his home this morning, presumably of a heart attack. One of the more popular stars on the mega-popular show, he is best remembered for this catch-phrase:

He will be missed. What will not be missed, however, is this commercial for the Welcome Back, Kotter "Up Your Nose with a Rubber Hose" board game which is perhaps one of the most grating ads of all time.