"He was certainly a hero to all of us," showrunner Al Jean recalls.

Stephen Hawking was as much of a treasure in the entertainment world as he was in the scientific world.

The theoretical physicist, best-selling author and University of Cambridge professor — who died Wednesday at the age of 76 — forever changed how people looked at the stars. He also had a killer sense of humor.

Among the numerous TV shows he appeared on, The Simpsons was his first sitcom. Everyone at the show adored him, showrunner Al Jean told The Hollywood Reporter on Wednesday.

"One thing about him that is maybe not as well known, he had a tremendous sense of humor," Jean said. "He would tell jokes when he came to our table reads, which he did several times."

The world-renowned scientist first appeared on the Fox cartoon in May 1999 on the season 10 episode, "They Saved Lisa's Brain."

Playing himself, Hawking goes to Springfield after the town becomes under control of its newly created Mensa chapter. The power, of course, goes to the group's head and it is a visit by Hawking, who expresses displeasure with the group's arrogance, that helps make things right.

"What we would do is send him the script and then he would record it through his machine," Jean explained. "So it was his voice, his special audio program. He did come to studio when he was in America, but he didn't ever go to the record."

Arguably one of the most classic jokes — not only of the episode, but the entire series — comes toward the end, after Hawking says his piece and Homer yells, "Larry Flynt is right! You guys stink!"

Jean said that gem was all him.

"Mr. Hawking read it and allowed it," Jean said. "The joke is Homer is an idiot. In no way was it critical of Mr. Hawking."

But, there was a gag Hawking wanted to avoid.

"He did say at one point that he did not want to be drunk onscreen," Jean said. "That was the only note we got from him. He didn't mind having a beer with Homer at Moe's [in the end of "Lisa's Brain"], but not more."

Calling him the "smartest" guest the show ever welcomed, Jean noted that Hawking was as big a rock star as any other celebrity when he dropped by the studio.

"Everyone wanted to get their picture taken with him," he said. "It was an honor to be able to briefly interact with the Albert Einstein of our time. I still can't get over it."