Goku, who had turned into a Great Ape after he looked at the full moon, breaks out of Emperor Pilaf's cell, and starts to destroy Pilaf's Castle. Pilaf, Shu and Mai, who are all sleeping at the time, wake up and realize that something is destroying Pilaf's Castle. Pilaf gets angry and tells Shu and Mai to do something about it. Shu and Mai are only in their pajamas and have no choice but to throw objects that are in the bedroom at the giant ape, such as pillows and slippers; obviously, this had no effect on the monster. The ape then continues to destroy the castle and chase the trio. They head to an airplane where they escape from the castle.
Yamcha, Oolong, Puar and Bulma are all trying to run from the castle, but Bulma ends up tripping and spraining her ankle. With Oolong and Puar not being strong enough to help her up, Yamcha has to get over his fear of women and helps Bulma get away to safety; she is very thankful for this. Meanwhile, angry over the destruction of his castle, Pilaf tells Mai to turn around. Their plane starts shooting Goku but seems to have no affect on him. The plane then brings out a heat seeking missile and knocks the Great Ape Goku out.
Everyone then believes that Goku is really dead and Pilaf begins jumping up and down on his tail. Shu and Mai then recognize that the ape's hands are starting to twitch and cower in fear. Great Ape Goku wakes up and chases Emperor Pilaf and his two henchmen who then run off back to their plane and try to escape. They fly off but Goku throws a tower at the plane causing it to crash. Yamcha finds Bulma stuck under another tower of Pilaf's castle. Yamcha lifts up the tower to let Bulma out but then they are chased again by Goku. The Ape picks Bulma up and she screams until she passes out then Goku starts to lick her, seemingly intent on eating her.
Puar then mentions that Goku's weak point is his tail, so Yamcha uses his power of the Wolf Fang Fist to break the castle and makes a sword out of stone, and he tries to cut off Goku's tail. This has no effect, however, and the sword shatters to pieces because it was not sharp enough to cut the tail off. Yamcha then grabs on to Goku's tail helped by Oolong, while Puar turns into a pair of scissors and cuts it off. Goku drops Bulma and shrinks down back to his normal form, where he ends up naked and unconscious. Pilaf is sad about his castle, and he orders Mai and Shu to shoot them all. Pilaf then runs in the other direction and, when Shu and Mai see this, they decide to run away with Pilaf as well.
The next morning, Goku does not remember a thing about his transformation the night before, so the rest of the group agree not to tell him about it and the fact that he is probably the monster that killed his Grandpa Gohan. Goku then finds out that his tail is gone and assumes it ran way and is given Oolong's pants to cover up. Afterwards Goku goes back to the ruins of Pilaf's castle to get his Power Pole. Bulma is now mad that she was not able to get a boyfriend and Yamcha is mad because he is going to still be shy around girls for another year, but they then look at each other and gleefully decide to be boyfriend and girlfriend. When Goku returns, Bulma gives him her Dragon Radar so that he will be able to go get his grandpa's Dragon Ball in a year when they come back to normal. They decide to part ways, Bulma and Yamcha plan to go back to the city with Puar and Oolong tagging along. Yamcha then takes out a Jet capsule and takes off with everyone else. Goku then gets on his Flying Nimbus and starts to head to Master Roshi's island for training, waving goodbye to Bulma, Yamcha, Oolong, and Puar.
- Pilaf, Shu and Mai vs. Goku (Great Ape)
- Yamcha, Puar and Oolong vs. Goku (Great Ape)
Great Ape Transformation: Goku
Differences from the manga
- Pilaf commanding Mai to drive the plane back where they fire ammunition at the Great Ape and he falls.
- Pilaf getting out of the plane and jumping on the Great Ape's tail.
- Yamcha attempting to cut Goku's tail using a sword he made out of stone.
- After the plane is destroyed, Pilaf gives Shu and Mai two guns and tells them to go fight Bulma and the others off and runs away but Shu and Mai do not listen to him and run off as well.
- Great Ape Goku's rampage was extended.
- When Goku turns back into his normal form there is a badly drawn flower covering his private area as an edit in the Ocean Group Dub.
- In the Japanese version, the narrator's speech at the ending says something along the lines of Goku and friends' adventures finally being at an end. He then gives a "just kidding" conclusion to this speech, and informs the viewers that the adventures will continue next week.
- This was the final episode of the early Ocean Group dubbed version of the show.
- The scene where Emperor Pilaf is shooting Great Ape Goku with his plane is reminiscent of King Kong.
- When Yamcha clenches his teeth before he saves Bulma, he has all of his teeth, including the one he lost during the fight with Goku.
- Oolong asks if Goku is an alien, a question that is answered much later, in Dragon Ball Z.
- Bulma and the others decide not to tell Goku that has was responsible for killing his grandfather when he turned into a Great Ape. However, Goku finds out that he was the one that killed his grandfather in the Dragon Ball Z episode "Spirit Bomb Away!", apologizes for what he did, and handles the truth.
- Goku's tail is cut off for the first time, but it is later grown back in "Monster Beast Giran".