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.
Gilligan is bitten by a bat, and then dreams that he has turned into a vampire. Fortunately the Professor knows about bats (what DOESN'T he know about?!), and is able to identify the bat that bit Gilligan as a common red fruit bat, rather than a vampire bat.
Gilligan meets his double, a foreign spy who has undergone plastic surgery in order to look like Gilligan (why, we're not sure!). Gilligan gets in lots of trouble as his double steals Mary Ann's pies, etc . . ..
Gilligan finds a crate of radioactive vegetable seeds. The plants grow quickly and grossly misshapen, but the Castaways are so hungry for new items in their diet that they consume them quickly. The plants, when eaten, give the castaways super-human powers. Of course, after he realizes that the vegetables are radioactive, the Professor saves the day by making a homemade soup to absorb the radioactivity.
Famous Hollywood director Herald Hecuba lands on the island during his world-wide talent search. The castaways put on a musical version of Hamlet in order to impress the director, with hopes that he will take them back to Hollywood when he leaves.
A witch doctor makes voodoo dolls from the Castaways' personal objects, which he has stolen from their huts. Gilligan stumbles upon the hidden voodoo dolls and brings them back to the Castaways. He then fashions a voodoo doll in the likeness of the witch doctor, to fight fire with fire! Even though the Professor was turned into a motionless zombie for a short time, he refuses to acknowledge a scientific acceptance of voodoo.
Mr. Howell revises his will, and leaves a large chunk of his estate to each castaway. They decide to throw him a party to show their appreciation, but when he overhears them talking about which one of them is going to have to ""cut the pigs throat"" he thinks they are planning to kill him in order to collect their inheritance. Later, he discovers that they have actually trapped a wild boar in an effort to serve him bar-b-que spareribs as a surprise.
Lord Beasley Waterford, a famous butterfly collector, lands on the island searching for the world's rarest butterfly, the pussycat swallowtail. While he vows that he will not leave the island until he has found his prey, the castaways eagerly try everything to persuade him to fire his flare gun early. He (like all of the other visitors to the island) leaves without sending help.
Gilligan wakes up with white hair, and thinks he overhears the Professor say that he has a rare disease that has made him age quickly (the disease? ""follicular albinism""). When Mrs. Howell attempts to fix the problem by dyeing Gilligan's hair brown, the dye causes his hair to fall out. A classic line occurred as the other Castaways tried to act as though they don't notice Gilligan's baldness â€¦ Mrs. Howell's famous breakfast order: ""I think I'll have a hard-bald egg."" Later, the Skipper exhibits the same symptoms. The Professor determines the problems are caused by the crude bleach that Gilligan and the Skipper have been using while washing the castaways clothing.
A mad scientist lands on the island, and makes the castaways work for him through the use of rings that, when placed on their fingers, cause them to fall under a hypnotic trance. What are his evil plans? To use the hypnotized castaways to rob Fort Knox!
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!
While fishing, Gilligan and the Skipper reel in a briefcase, stamped with the words ""Property of the U.S. Government."" Everyone believes that the case contains top secret government material. Gilligan accidentally handcuffs the briefcase to his wrist, and has a wild dream about secret agents, evil enemy spies, and deadly spy games!
Someone kidnaps Mrs. Howell, Mary Ann, and Ginger, and then demands ransom money. The kidnaper turns out to be a compulsive gambler who fled civilization to avoid temptation. While the Castaways attempt to rehabilitate him, he ends up leaving the island, accompanied by Mrs. Howell's pearl necklace, Mr. Howell's wallet, and Ginger's earrings!
One by one, all of the Castaways mysteriously disappear. Gilligan then dreams that he is Dr. Jekyll and Mr. Hyde. In the end, Gilligan rescues them from the hidden World War II munitions pit that they have all fallen into.
A drab, plain-jane woman lands on the island seeking privacy. The girls give her a beauty make-over to lift her spirits, and she ends up looking like Ginger's twin. While the castaways were hoping to lift her spirits enough so that she would want to return to civilization (she has a boat, but has hidden the key), she ends up leaving them on the island and going back to Hollywood to attempt to assume Ginger Grant's movie career.
Gilligan is made a deputy sheriff, and begins to take his job too seriously. He ends up locking everyone up in a make-shift jail, including himself! Of course, while the castaways are locked up tight, another potential rescue plane flies over the island.
George Barkley enters the ""Take a Dare Contest"". He will receive $10,000 if he can spend a week alone on an island, fending for himself. However, he is not alone on the island on which they drop him. Once again, however, rescue eludes the castaways as Mr. Barkley deduces that he can not tell anyone about the castaways without having to forfeit the $10,000 for not spending the week alone.
The Castaways hear on the radio that the Maritime Board of Inquiry has blamed the Skipper for the Minnow crash. In an attempt to disprove the board's verdict, they reenact the shipwreck themselves, only to find out that the cause appears to be Gilligan's ineptness. Later, a radio update reports that the Board of Inquiry has cleared the Skipper of the charges, as the Weather Service mistakenly read the wrong forecast that morning causing the crew to be unaware of the impending storms.
Famous big-game hunter Jonathan Kincaid and his assistant, Ramoo land on the island in search of new game to hunt. Since they have hunted just about every kind of animal on earth, they then decide that the ultimate challenge would be to hunt a human. After much debate, they choose Gilligan as their target, and state that if Gilligan can stay alive for 24 hours, they will rescue the castaways. After Gilligan manages to outwit and outrun the armed hunters for 24 hours, Kincaid does not uphold his promise of rescue for fear they will report him to the authorities.
Mrs. Howell starts receiving mysterious love notes, and the source remains a mystery until Mr. Howell is caught in the act. Mrs. Howell dreams that she is Cinderella, and Gilligan is her fairy godfather. The Professor rigs up a lie detector using the ship's horn and batteries from the radio.
An loin-cloth clad ape-man (Tongo) comes to the island, and makes off with their food and supplies. Actually, he is an out of work actor, who tries to convince the Castaways that he is a real uncivilized ape-man while studying for an upcoming role. After he cowers when confronted by a ""real"" gorilla, he leaves the island and the Castaways behind.
Lightning strikes Gilligan during Skipper and Gilligan's bowling tournament, and his stone bowling ball becomes molecularly attached to him. The Professor tries to help Gilligan, but ends up causing him to become invisible.
The Professor determines that a manned space craft will pass over the island, and attempts to fashion a telegraph machine. When that fails, the Castaways try to spell out SOS using burning logs as a rescue signal, but Gilligan catches fire and runs into the logs, causing them to spell out SOL, the name of one of the astronauts! Blooper watch: as Gilligan is lighting the logs, you can see his pants smoking before he backs up into the flaming logs!
Gilligan and the Skipper find an ancient Kupaki totem pole which is topped with a head that looks just like Gilligan. When fierce Kupaki headhunters come to the island, Gilligan must convince them that he is their ""mashuka"" or sacred ancestor.
Mary Ann falls backwards while watching Ginger perform on stage, and, when she awakens, she thinks that she is Ginger. Meanwhile, Gilligan accidentally watches as the Professor attempts to hypnotize Mary Ann, and thus he begins to think that he is Mary Ann.
Gilligan discovers some ancient stone tablets that the Professor thinks may contain the secret of getting them off the island. That night, Gilligan dreams that he is a caveman chiseling a story on a stone tablet three million years ago.
After Gilligan saves a beautiful native girl from drowning, she vows to be his slave forever. Later, her ex-boyfriend comes to the island and challenges Gilligan to a duel to the death. The Professor concocts a drug to cause Gilligan to fall into a catatonic state, so that the natives will think he is dead, but they then insist on a native funeral . . . by burning the body!
A U.S. Air Force jetpack washes ashore in the lagoon. After close inspection of the jetpack, the Professor determines that the tanks contain just enough fuel to carry Gilligan to Hawaii. However, that determination was made before Gilligan wasted most of the fuel while proceeding to goof-up several attempts to be discovered and rescued. While flying the jetpack near where Navy search vessels are reported to be lurking, Gilligan is so scared by a radio report of an ""Unidentified Flying Object in the area"" that he blasts higher and hides in a cloud, not realizing that the UFO the Navy ships see is actually him with the jetpack!
The Professor sees the arrival of a homing pigeon on the island as an opportunity to be rescued, and immediately begins to feed it a special diet designed to strengthen it so that it can fly again. In an attempt to speed the recovery time, the other Castaways also feed the pigeon, causing it to become too fat to fly. The pigeon is also trapped for a short while in a cave by a ""deadly six-foot black morning spider.""
A crate that washes ashore contains a top secret plastic explosive developed by the US Government. The Castaways make use of the plastic in a variety of objects, including nails for the Skipper, dishes for Mary Ann, jewelry for Ginger, golf balls for Mr. Howell, and even fillings for Gilligan's teeth, unaware that once hardened it becomes a dangerous explosive which will detonate on impact!
King Killiwani and two other natives come to the island looking for a 'White Goddess.' Ginger and Mary Ann are likely candidates, until the Castaways discover that the natives plan to take the ""White Goddess"" back to their island to marry a volcano and then be sacrificed into it. After seeing Gilligan in a wig and heels, the natives choose him as the ""White Goddess.""