Gilligan's Island - Season 3 - Eps 10: Topsy-Turvy
Gilligan bumps his head and suddenly sees everything upside down. The Professor tries to help by brewing an antidote made of keptibora berry extract, but the antidote causes Gilligan to see double. After consuming more juice, he sees four of everything. Meanwhile, the island is invaded by three headhunters who slowly capture all of the other castaways. Gilligan saves the day by serving the headhunters lots and lots of keptibora berry extract, which causes them to see ""hundreds"" of castaways running toward them!
About Gilligan's Island

Title: Gilligan's Island
First Air Date: 1964-09-26
Last Air Date: 1967-04-17
Status: Ended
Rating: 7.431/10 (from 238 votes)
Language: EN
Seasons: 4
Total Episodes: 98
Network: CBS
Genres: Comedy, Family
Production Companies: United Artists Television, CBS, Gladysya Productions
Synopsis
The slapstick adventures of hapless Gilligan, long-suffering Skipper and their gang of mismatched castaways, all stranded on an uncharted desert isle after their tiny ship hit stormy weather.
Cast

Bob Denver
Gilligan

Alan Hale Jr.
Jonas "The Skipper" Grumby

Jim Backus
Thurston Howell, III

Natalie Schafer
Eunice "Lovey" Wentworth Howell

Tina Louise
Ginger Grant

Dawn Wells
Mary Ann Summers

Russell Johnson
Roy "The Professor" Hinkley