Stephen Furst worked as a pizza delivery driver while looking for acting jobs in the mid-1970s, and included his head shot in pizza boxes. After Matty Simmons saw his photo, Furst was cast as Flounder in National Lampoon’s Animal House (1978). He reprised this role in the 1979 spin-off series Delta House. Others include ‘Junior’ Keller in The Unseen (1980), as Gonzer in the feature film Up the Creek (1984), as Dr. Elliot Axelrod in the television series St. Elsewhere (1983–1988), and as Vir Cotto in the science fiction television series Babylon 5 (1994–1998). Furst was amused by the report that North Korean dictator Kim Jong Un modeled his haircut after Furst’s character in Babylon 5. In 1979 he played the role of an overweight high school tuba player coerced onto the wrestling team in Kieth Merrill’s feel-good underdog film, Take Down. Also in 1979, as pointed out above, Stephen Furst reprised the Flounder character in the ABC sitcom Delta House. He also reprised the character and repeated his famous line, “Oh boy, is this great!” in the Twisted Sister music video for “I Wanna Rock.”

In 1980, Stephen Furst played the character of Harold in the cult classic movie, Midnight Madness, and the character of “Junior” Keller (the unseen) in the horror movie The Unseen. In 1983, he also appeared in a supporting role as Aldo in the provocative ABC TV movie The Day After. In 1989, he played the character of Albert Ianuzzi in the film The Dream Team. In 1983, Furst also appeared in an episode of CHiPs titled “Fun House,” alongside Erik Estrada, Tom Reilly, and Heather O’Rourke; in this installment, Furst acted out a student who belonged to the college fraternity “DDT.” In the 1995 animated TV series Freakazoid!, he voiced the character Fanboy. Also in 1995, he took a hiatus from Babylon 5 to star in a short-lived TV series, Misery Loves Company. In 1997, he played Derby Ferris in Little Bigfoot 2: The Journey Home. He also voiced a young Colonel Hathi in Season 2 of Disney’s Jungle Cubs, had a starring voice role as Booster in the 2000 series Buzz Lightyear of Star Command, and also played a hulky walrus named Dash in the 2000 Disney movie The Little Mermaid II: Return to the Sea. He starred in Magic Kid and its sequel. In 2002, he guest starred in an episode of Scrubs.

Stephen Furst directed many independent and/or low-budget movies, including the 2001 low-budget movie Title to Murder, starring Christopher Atkins and Maureen McCormick, and the direct-to-video children’s movie Baby Huey’s Great Easter Adventure. He also directed three low-budget movies for the Sci Fi Channel: Dragon Storm in 2004, Path of Destruction in 2005, and Basilisk: The Serpent King in 2006; he additionally co-starred in the last two films. Furst produced My Sister’s Keeper, based on the Jodi Picoult novel, starring Cameron Diaz and Alec Baldwin. He produced other several films under his production company Curmudgeon Films. Atomic Shark aired in August of 2016 on Syfy, during “Sharknado Week”. Christmas in Homestead premiered on the Hallmark Channel during the holiday season of 2016. Cold Moon, a psychological thriller based on the Michael McDowell book, is set for a theatrical release in October 2017 in the United States. Cold Moon won “Best Horror Film” at the 2016 Laughlin Film Festival. On June 16, 2017, Furst died from complications related to diabetes at his home in Moorpark, California, at age 63.