Bob Einstein, the U.S. comedian, writer and actor best known for his role as Super Dave Osborne, has died of cancer. He was 76.

Einstein was also known for his roles as "professional surrogate" Larry Middleman on Arrested Development and Marty Funkhouser in HBO's Curb Your Enthusiasm, where he played the aggravating friend of Larry David.

His brother and fellow actor Albert Brooks tweeted the news Wednesday, calling Einstein a "brilliantly funny man" who will be "missed forever."

R.I.P. My dear brother Bob Einstein. A great brother, father and husband. A brilliantly funny man. You will be missed forever. —@AlbertBrooks

Bob Einstein's manager, Lee Kernis, confirmed to CBC News that Einstein died of cancer.

Einstein was born in 1942 in Los Angeles to actress Thelma Leeds and comedian and actor Harry Einstein, also known as Harry Parke.

In the 1960s, Einstein created the character of Super Dave Osborne, a fearless but accident-prone daredevil who made appearances on The Smothers Brothers Comedy Hour and other comedy/variety shows.

"This character allows me to do anything I want, comedically, and get away with it," the comedian told The Associated Press in 1995.

Some of Super Dave's most memorable feats involved jumping off Toronto's CN Tower and being crushed by an 11-tonne wrecking ball.

R.I.P. Stewart Robert Einstein also known as stuntman 'Super Dave Osborne'<br><br>Here's a clip of his first stunt <a href="https://t.co/As8RSl1ymW">pic.twitter.com/As8RSl1ymW</a> —@SInow

Einstein, along with his Canadian partner, Allan Blye, won two Emmy awards for their comedy writing. Their first came for work on the Smothers Brothers Comedy Hour in 1969, and their second came for their writing on Dick Van Dyke's Van Dyke and Company series in 1977.

Einstein also wrote for shows such as the Sonny and Cher Comedy Hour and Pat Paulsen's Half a Comedy Hour, and he appeared regularly on late night talk shows with Johnny Carson, David Letterman and Jimmy Kimmel.

Bob Einstein, the U.S. comedian, writer and actor best known for his role as Super Dave Osborne, has died of cancer. He was 76. 1:17

In 1979, Einstein and Blye created Bizarre, a sketch-comedy show filmed in Toronto that aired from 1980-86 on CTV in Canada and Showtime in the United States.

Kernis said Wednesday that Einstein "loved his time in Canada," where fans watched Super Dave optimistically attempt harebrained stunts for decades. The character became a regular feature on Bizarre, and was spun off into several TV series in Canada and the United States, most recently Super Dave's Spike Tacular in 2009.

Over time, Super Dave even made it into commercials for clothes and athletic shoes. Einstein said he never tired of his alter ego.

'We're all in a state of shock'

Einstein was scheduled to be part of the 10th season of Curb Your Enthusiasm but his health barred him from filming, HBO said Wednesday.

In a statement, Larry David the star of the long-running series, said he'd never seen an actor enjoy a role more than Einstein did playing Marty Funkhouser.

"It was an amazing, unforgettable experience knowing and working with him. There was no one like him, as he told us again and again," David said Wednesday. "We're all in a state of shock."

"What a mind! What a great friend," tweeted comedian David Steinberg, who started out with Einstein on the Smothers Brothers show.

Fellow Curb Your Enthusiasm actor Richard Lewis tweeted that Einstein's "long career is hard to match. His role on [the show] was excruciatingly brilliant! Our cast and crew will be devastated. He was so loved."