Mull’s daughter Maggie says her father passed away at home “after a valiant fight against a long illness.” This was posted by Maggie on Instagram
He was renowned for his exceptional abilities in all creative fields and for his work on Red Roof Inn advertisements,” the author stated.

He would find that joke funny.” He always had a sense of humor. Many people adored my dad: his wife and daughter, his friends and colleagues, other performers, comedians, and artists, and most importantly, a huge number of dogs. I cherished him dearly.

Mull’s most well-known roles were likely in the comedy of the same name, when he played Roseanne Connor’s friend Leon Carp and Sabrina the Teenage Witch principal Willard Kraft.
He also portrayed Arrested Development’s private eye Gene Parmesean.

In 2016, Mull received a single Emmy nomination for his Veep character Bob Bradley.
Among the numerous roles Mull performed in his career was co-writing, alongside Fred Willard, the mockumentary The History of White People in America in 1985.