Two young brothers secretly bring home a seal from their summer vacation and try to hide it from Mom and Dad. Havoc ensues as Sammy's antics disrupt the quiet town of Gatesville and its unsuspecting residents.
| Actor | Role |
|---|---|
 Michael McGreeveyArthur Loomis | Arthur Loomis |
 Bill MumyPetey Loomis | Petey Loomis |
 Jack CarsonHarold Sylvester | Harold Sylvester |
 Robert CulpChester 'Chet' Loomis | Chester 'Chet' Loomis |
 Ann JillianPorsche 'Rocky' Sylvester | Porsche 'Rocky' Sylvester |
 Patricia BarryHelen Loomis | Helen Loomis |
 Elisabeth FraserLovey Sylvester | Lovey Sylvester |
 Renie RianoMrs. Crotty | Mrs. Crotty |
 Mary MitchelSue Foster | Sue Foster |
 Claude StroudBen | Ben |
 Bill BaldwinParty Guest (uncredited) | Party Guest (uncredited) |
| BBenjie BancroftParty Guest (uncredited) | Party Guest (uncredited) |
 Tommy FarrellParty Guest (uncredited) | Party Guest (uncredited) |
 Shep HoughtonParty Guest (uncredited) | Party Guest (uncredited) |
| JJoseph La CavaWaiter (uncredited) | Waiter (uncredited) |
| LLuree WieseWaitress (uncredited) | Waitress (uncredited) |