Historical clue formulations

• TV alien played by Robin Williams — 2021-07-14
• Breakout role for Robin Williams — 2020-04-07
• Robin Williams role that was out of this world? — 2015-11-02
• Sitcom alien — 2015-03-22
• Sitcom character who curses by shouting "Shazbot!" — 2015-01-01
• TV character who said "K.O." instead of "O.K." — 2012-11-23
• Sitcom father of Mearth — 2009-03-11
• TV alien — 2006-07-23
• Robin Williams TV character — 2003-11-23
• TV character first seen on "Happy Days" — 2003-04-13
• 70's-80's TV alien — 1999-03-15