10 Classic TV Series You Didn't Know Were Spinoffs
4. Mork and Mindy (1978-1982) 
Spun off from: Happy Days
Spun off from: Happy Days You would be hard pressed to find a better example of a breakout role than that of Mork from Ork. As written, the role could barely contain its star, a manic, Julliard-trained comic, and within a few years Robin Williams was one of the most bankable movie stars in the world.
Mork was an alien assigned to study earthlings and report back to his superior on Ork, the rotund Orson, who was never seen on camera but was based on the aging, overweight actor/director Orson Welles. Mork settled in Boulder, Colorado, with a woman named Mindy, played by Pam Dawber. He had a few bizarre little powers, mainly in his index finger, and the comedy was often improvised on set. But Williams frenzied performance was tempered with a degree of charm, and even this early in his career audiences could see that the comic had range. Although he was an alien from an advanced interplanetary race, his understanding of human relationships was often that of a childs, fodder for great comedy. But before landing in Boulder this bizarre alien from the planet Ork appeared in a fifth season episode of Happy Days, arriving on Earth to take Richie Cunningham (Ron Howard) back to his home planet. Mork and Fonzie (Henry Winkler) get into a bit of a mano-a-mano confrontation and Richie is spared. The episode proved so popular that producer Garry Marshall got the green light to give Mork a show of his own. While a huge ratings hit in its first season, fiddling by the network brought about a significant decline in the shows popularity. But despite the waning ratings, Williams had established himself as a huge comic talent and embarked on a successful career.