Mull’s daughter Maggie announced on Instagram that her father passed away at home “after a valiant fight against a long illness.”

Maggie shared that her father was widely admired for his incredible talent across various creative fields, particularly for his work on Red Roof Inn advertisements. She also reflected on his ever-present sense of humor, adding, “He would find that joke funny,” and highlighting how much he was loved by many—his wife and daughter, friends, colleagues, fellow performers, comedians, artists, and even a vast number of dogs. Maggie expressed how deeply she cherished him.

Mull was perhaps best known for his roles in the comedy Roseanne, where he played Roseanne Connor’s friend Leon Carp, and in Sabrina the Teenage Witch, where he portrayed Principal Willard Kraft. He also took on the memorable role of private eye Gene Parmesean in Arrested Development.

In 2016, Mull earned an Emmy nomination for his portrayal of Bob Bradley in Veep.

Throughout his career, Mull was known for his versatility, which extended to co-writing the 1985 mockumentary The History of White People in America alongside Fred Willard.

A passionate comedy and songwriting enthusiast, Mull also gained recognition in the world of music. His song A Girl Named Johnny Cash, a parody of the classic A Boy Named Sue, was released in the early 1970s by country music icon Jane Morgan. The song reached number one on Billboard’s Hot Country Songs chart, where it stayed for five weeks.