Palillo, who later taught at a high school himself, died of a heart attack in Palm Beach Gardens Aug. 14. He was 63.
He told the Akron (Ohio) Beacon Journal in 1997 the goofy character on the ABC sitcom "Welcome Back, Kotter" in many ways hurt his acting career because he was so strongly identified with it.
"I know him, love what he does, not right for the part," Palillo said casting directors consistently told him after his years on "Kotter."
"Everybody thought of me as Arnold Horshack. I resented Horshack for so many years," he told the newspaper, explaining he thought that TV and film producers "could smell the desperation in me."
"Kotter," which aired 1975-79, also featured a young John Travolta, who went on to many box office successes. But Travolta was the only actor from the show to become a movie star.
The show starred Gabe Kaplan as a high school teacher returning to his alma mater in Brooklyn to take over an unruly class of remedial students known collectively as the Sweathogs, because their top-floor classroom was always hot.
Horshack was known for several catchphrases, including "Ooh, ooh, Mista Kahta! Mista Kahta!" which he said when he raised his hand excitedly in class thinking incorrectly he had the right answer, and "That was ver-ry impressive, Mista Kahta!" in faint praise for Kotter's teaching and jokes.
Palillo -- whose last name was spelled "Paolillo" by the local Howard-Price Funeral Home -- eventually made peace with his typecasting, longtime Palm Beach Gardens friend Stacy Sacco told The Palm Beach Post.
"He appreciated that it was such an iconic character," she said. "And he would absolutely do that imitation."
Palillo -- who taught drama at the G-Star School of the Arts charter school in Palm Springs, Fla., when he died -- got supporting roles on TV series including "The Love Boat" and "The A-Team."
He also appeared in 12 films, with his last the 2010 action comedy "The Guardians," about a con man who gets conned.
In addition, he directed musicals in Los Angeles and West Palm Beach, and in 2005 had his first full-length play, "The Lost Boy," about "Peter Pan" author J.M. Barrie, staged at the Helen Hayes Theater in Nyack, N.Y., and at the Queens Theater in the Park in New York City.
An artist who illustrated the children's books "The Red Wings of Christmas" and "A Gift for the Contessa," Palillo also introduced a line of limited-edition T-shirts in 2007. The company making the shirts was named Rotter and Friends.