The series was a spinoff of the sitcom Happy Days. The character of Mork (Robin Williams) first appeared in the Season 5 episode, "My Favorite Orkan," where he threatened to take Richie Cunningham back to Ork as an example of a human, but his plan is foiled by Fonzie. The character proved to be popular enough with the audience to rate a starring role in a series, though in the series Mork would reside in Boulder Colorado, and in the (then) current day of 1978 as opposed to Happy Days' 1950s Milwaukee Wisconsin.