John Lithgow as George Henderson

Melinda Dillon as Nancy Henderson

Margaret Langrick as Sarah Henderson

Joshua Rudoy as Ernie Henderson

Kevin Peter Hall as Harry

David Suchet as Jacques Lafleur

Lainie Kazan as Irene Moffitt

Don Ameche as Dr. Wallace Wrightwood

M. Emmet Walsh as George Henderson Sr.

Laura Kenny as 'Mouse' Woman

William Ontiveros as Sgt. Mancini

David Richardt as Dirty Harry Officer

Jacqueline Moscou as DMV Clerk

Richard Arnold as 'Mouse' Spouse

Sean Morgan as Jerry Seville

Chuck McCollum as Guard

Nick Flynn as Stuart

David MacIntyre as Billers

Peggy Platt as Librarian

Orene Anderson as Woman in Kitchen

William Dear as Sighting Man

Laurie O'Brien as Screaming Woman

Michael J. Loggins as Big Gun Man

James King as Bicycle Man

Nathaniel Ellis as Sgt. Bader

Juleen Murray as Press Woman #1

Connie Craig as Press Woman #2

Dana Middleton as News Anchor #1

Mark Mitchell as Press Man #1

Richard Foley as News Anchor #2

Larry Wansley as News Anchor #3

Steve Brodie as News Anchor #4

Mickey Gilbert as Police Officer

Tom Hammond as Police Officer

Stuart Schwarz as SWAT Officer

Justin Mastro as Vigilante

Michael Goodell as Pool Man

Vern Taylor as Jerome

Stan Sturing as Police Clerk

Robert Isaac Lee as Kim Lee

Debbie Lee Carrington as Little Bigfoot

John Bloom as Feet

Britches as Little Bob

Fred Newman as Harry (voice)

William Frankfather as Schwarz