How Robin Williams Made A 'Horrible' Happy Days Script Worthy Of The Mork & Mindy Spinoff

No matter the profession, it's hard to say no to the boss. That was certainly the case in the "Happy Days" writers room in 1978. That is when show creator Garry Marshall asked the writers to develop a concept for the next episode that was out of this world. For a show about the idyllic 1950s (albeit through a white, middle-class, Midwest lens), introducing an alien into the show's narrative was a planet-sized challenge.

Selling the concept of an alien landing on Earth and taking Richie Cunningham (Ron Howard) back to his planet to study was foreign to a writing team that was rooted in wholesome reality. But somehow, the wild idea — and very limited preparation time — ended up being the saving grace for the writers. Desperate for an actor to play the role of the alien, a little-known comedian named Robin Williams stepped in and not only saved the episode, but spawned an entirely new sitcom from his single performance.

Why not, they already 'jumped the shark'

As absurd as an alien on the show sounds, the writers were getting desperate for ideas. Season 5 of "Happy Days" started with a three-episode arc where Fonzie is invited to Hollywood to make it big. In "Hollywood: Part 3," Fonzie accepts a challenge to water-ski jump over a shark (all the while in his leather jacket). The episode was so silly it inspired the phrase "jump the shark." Ever since, when a sitcom wears out its originality and ramps up the absurdity, it is said to have "jumped the shark."

By the middle of season 5, show creator Garry Marshall had begun taking advice from his 8-year-old for episode ideas. According to Gizmodo, it was Marshall's son who suggested an alien drop in on Milwaukee and pay a visit to The Fonz, and maybe bring a human back to his home planet of Ork to study. With just days to go until production on the episode, "My Favorite Orkan," the writers had no option other than to run with the idea. Writer Brian Levant told Gizmodo:

"We looked at each other like, 'God, that's the most horrible idea I've ever heard.' We drew straws to see who drew the short straw and had to write the script."

In an interview with the Television Academy, "Happy Days" star Ron Howard said the episode "didn't read so great" and that ABC wanted to throw the episode out. Marshall fought for the episode and won. But there was another problem: They couldn't find anyone willing to play the alien.

Robin Williams wasn't supposed to be Mork

Robin Williams was not the first choice to play the alien Mork, but rather a Hail Mary to save the episode. British actor Roger Rees, who TV audiences might best remember as the smooth-talking millionaire Robin Colcord on "Cheers," was initially cast as Mork. When he dropped out, they turned to Dom DeLuise, who rejected the offer. A third actor also said no upon reading the script. Rehearsals began that week without casting in place for the character that was the inspiration for the episode.

Finally, an associate producer remembered a stand-up comic who included a "spaceman" bit in his act. That comedian was Robin Williams, someone Ron Howard called "a guy that no one knew." The very next day, Williams blew everyone away during rehearsals. Writer Brian Levant told Gizmodo:

"They called us down for the most amazing run-through in the world. We saw one guy who embodied all three Marx Brothers, Chaplin, the Three Stooges, and William F. Buckley in the same body."

The writers quickly revised the script to incorporate ideas Williams brought to the rehearsal. Many of Mork's alien mannerisms, like drinking through his finger, came straight from Williams. The result was an episode so magical it even impressed The Fonz. Henry Winkler would later tell The Guardian: "I'm in the presence of greatness and my job here is to get out of his way." Fan mail and phone calls to ABC followed, and ABC responded by quickly creating a spinoff sitcom for Williams, "Mork & Mindy."

"Mork & Mindy" ran for four seasons and launched Williams in the American pop culture zeitgeist. Rather than jumping the shark, Williams took "the most horrible idea" ever and turned it into one of the most memorable episodes in "Happy Days" history, all the while saying "Nanu Nanu" to television audiences around the world. Or maybe even the entire galaxy, if you include the planet Ork.