Nanu Nanu, Mork

Before he was John Keating, Mrs. Doubtfire or Peter Pan, Robin Williams — who died Monday at the age of 63 — first grabbed viewers’ hearts on the small screen as an alien named Mork.

Following a stint as a writer for the short-lived Richard Pryor Show, Williams appeared on an episode of Happy Days as Mork, attempting to take Ron Howard’s Richie Cunningham back to his home planet of Ork. The character was so well received that ABC spun it off into its own show Mork & Mindy, which ran from 1978-1982, earning Williams his first Emmy nomination.

As Williams’ film career began to take off in the 1980s with The World According to Garp, Good Morning, Vietnam and Dead Poets Society, he still maintained a presence on the small screen, performing in stand-up specials — including his iconic An Evening at the Met in 1986 — and variety specials including Carol, Carl, Whoopiand Robin in 1987 and ABC Presents: A Royal Gala in 1988, for which he won Emmys, and Comic Relief on HBO with co-hosts Billy Crystal and Whoopi Goldberg.

Williams holds the distinction of being one of Johnny Carson's final two guests on The Tonight Show (Bette Midler was Carson’s last) and made guest appearances in many notable TV series over the years including Homicide: Life on the Street — which earned Williams another Emmy nomination — and a famous surprise cameo with Crystal in an episode of Friends. More recently, he played himself in an episode of Louie in 2012.

Last year, Williams attempted a full-time TV comeback as he co-starred with Sarah Michelle Gellar in the CBS comedy The Crazy Ones, which ran for only one season.

Nanu Nanu, Mork.