By Jeff Labrecque
Updated August 14, 2012 at 04:59 PM EDT
Frazer Harrison/Getty Images

Ron Palillo, whose nasally delivery made him one of the most memorable Sweathogs on the 1970s sitcom Welcome Back, Kotter, died last night in Palm Beach, Fla., suffering a heart attack in his sleep. He was 63.

Beginning in 1975, Palillo was one of the oddball students who tested Mr. Kotter for four seasons on the popular ABC show that also featured Gabe Kaplan and a young John Travolta. His character Arnold Dingfelder Horshack was always the first to raise his hand in class — “Ooo-ooo-oooooh!!” — and his wheezing staccato laugh was a punch line in itself.

In the 1980s, Palillo guested on several popular programs, including The A-Team, CHiPs, and Murder, She Wrote, and in 1996, he played himself on several episodes of Ellen. When acting opportunities became few and far between in 2002, he agreed to get in the ring with Dustin Diamond — a man 28 years his junior — for a bout of Celebrity Boxing billed as Horshack vs. Screech. In recent years, he had popped up on several TV Land nostalgia specials, but he’d found greater joy as an educator, teaching drama at the G-STAR School of the Arts for Motion Pictures and Broadcasting, a charter high school in West Palm Beach.

Palillo’s Welcome Back, Kotter co-star John Travolta said in a statement to EW: “Ron was a wonderful person and talent. And helped catapult Welcome Back Kotter to great success. We will miss him.”

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