Gilligan's Island - Season 3 Episode 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!