Robert Michael Morris, an actor best known for his work on HBO's The Comeback, has passed away at the age of 77, reports Deadline.

It's unclear how he died.

Morris spent many years teaching theater before he landed the part of Mickey, the hairdresser and one-man cheering section for Lisa Kudrow's Valerie Cherish, on The Comeback in 2005. The comedy lasted one season, but was such a cult favorite that HBO brought it back in 2014, with Morris reprising his role.

Kudrow also honored Morris after learning of his passing:

The Comeback creator Michael Patrick King, who studied under Morris in college, had high praise for the actor. "Robert Michael Morris was an inspiration to write for and to be around," he said. "His creativity was only matched by the joy and gratefulness he felt for each day he got to live his life as an artist."

Morris' greatest on-screen success certainly came later in life. In addition to The Comeback, he would also appear on How I Met Your Mother, The Middle, Will & Grace, 2 Broke Girls and Arrested Development.

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