The series is a spin-off from the sitcom Happy Days. The character of Mork is played by a then-unknown Robin Williams, who impressed producer Garry Marshall with his quirky comedic ability as soon as they met. When Williams was asked to take a seat at the audition, Williams immediately sat on his head on the chair and Marshall cast him on the spot, and later wryly commented that Williams was the only alien who auditioned for the role.
Mork appears in the Happy Days Season 5 episode, “My Favorite Orkan“, which first aired in February 1978 and is a take on the 1960s sitcom My Favorite Martian. Williams’s character, Mork, attempts to take Richie Cunningham back to his planet of Ork as a human specimen, but his plan is foiled by Fonzie. In the initial broadcast of this episode, it all turned out to be a dream that Richie had, but when Mork proved so popular, the ending was re-edited to show Mork erasing the experience from everyone’s minds, thus meaning the event had actually happened and wasn’t a dream.
Mork arrives on Earth in an egg-shaped spacecraft. He has been assigned to observe human behavior, by Orson, his mostly unseen and long-suffering superior (voiced by Ralph James). Orson has sent Mork, in order to get him off Ork, where humor is not permitted. Attempting to fit in, Mork dresses in an Earth suit, but wears it backward. He encounters 21-year-old Mindy (Pam Dawber) who is upset after an argument with her boyfriend, and offers assistance. Because of his odd garb, she mistakes him for a priest and is taken in by his willingness to listen (in fact, simply observing her behavior). When Mindy notices his backward suit and unconventional behavior, she asks who he really is, and he innocently tells her the truth. She promises to keep his identity a secret and allows him to move into her attic. Mindy’s father Fred (Conrad Janis) objects to his daughter living with a man (particularly one as bizarre as Mork), but Fred’s mother-in-law Cora (Elizabeth Kerr) approves of Mork and the living arrangement. Mindy and Cora work at Fred’s music store, where Cora gives lessons to Eugene Jeffrey Jacquet, a child who becomes Mork’s friend. Also seen occasionally are Mindy’s snooty old high school friend Susan (Morgan Fairchild) and the possibly insane Exidor (Robert Donner)
Not a great show but was a lot of fun to watch to see what Robin Williams was going to do next