MORK

Set to 5 different clues across 5 published puzzles, most often “Sitcom father of Mearth” — The New York Times, Wednesday, 11 March 2009.

4 letters

Every clue on record, most used first

Sitcom father of Mearthonce
The New York Times — Wednesday, 11 March 2009
TV alienonce
The New York Times — Sunday, 23 July 2006
Robin Williams TV characteronce
The New York Times — Sunday, 23 November 2003
TV character first seen on "Happy Days"once
The New York Times — Sunday, 13 April 2003
70's-80's TV alienonce
The New York Times — Monday, 15 March 1999