Primeape Goes Bananas (Japanese: おこらないでねオコリザル！Don't Get Angry, Okorizaru!) is the 25th episode of the Pokémon anime. It was first broadcast in Japan on September 16, 1997 and in the United States on October 9, 1998.
On their way to Celadon City, our heroes encounter Mankey, a wild Pokémon that if rubbed the wrong way can go into uncontrollable fits. Not realizing its unpredictability, the party accidentally upsets Mankey. To make matters worse, Team Rocket arrives and an all out war is waged by Mankey, who evolves into a ferocious Primeape, against anyone in its path. Will Ash be able to add Mankey/Primeape to his ever growing collection of Pokémon without having to withstand Primeape's unrelenting wrath?
Ash shows off his four Badges to Professor Oak, but Oak mentions that Gary and the other two Trainers from Pallet Town all have five Badges and have already passed through Celadon City. When Ash is infuriated, Oak advises that he should catch more Pokémon in order to become a better Trainer. He ends the call, leaving Ash upset.
Misty and Pikachu are eating rice balls as Misty notices Ash's mood. Ash mentions how far behind he is as Brock points down the path to Celadon City. Misty mentions that Ash needs to get there his own way as Brock mentions quality over quantity. At that moment, Pikachu notices a Mankey peeking from behind a rock nearby as Ash checks his Pokédex. Mankey hops over Brock, wanting the rice ball. It takes it and climbs atop a rock, eating it. Ash decides to catch it by merely throwing a Poké Ball at it. Mankey throws the rice ball which the Poké Ball catches, and it then hops off, clearly angry. The Pokédex mentions that once it goes into Thrash, it is hard to stop. Mankey charges and everyone runs away. Brock tries to stop it by throwing it a rice ball, but it destroys it with its fist. Misty trips and it appears Mankey will attack her, but it jumps off her head to lands on Ash's face, pounding him. Mankey leaves Ash beaten and without his hat as it climbs atop a tree and wears the hat. Nearby, Team Rocket watches, wanting to catch Pikachu and get a promotion. Meowth makes a smart remark as Jessie rolls a yarn ball at Meowth, pacifying the Pokémon.
Ash gets up and notices his hat is missing. Ash confronts Mankey as the Pokémon mocks Ash, imitating him twisting by his hat back and throwing the Poké Ball. Ash climbs the tree to reclaim the hat. He mentions that the hat was one he won at the Pokémon League Expo. A commercial flashback plays out and shows how rare the hat is. Misty remembers trying to win that hat, but Ash admits that he sent in multiple postcards. Ash manages to climb high enough, though Mankey beats him up and jumps off, sending Ash back down. Team Rocket steps out to confront them, but Mankey checks out Team Rocket. James kicks Mankey away. Brock tells Team Rocket to leave before it returns. Team Rocket turns, seeing the angry Pokémon evolving into Primeape.
Ash checks his Pokédex about Primeape as Team Rocket decides to ignore it, sending out Ekans and Koffing. Primeape attacks Jessie, sending her flying face-first into a rock. She gets angry and orders the Pokémon to attack Primeape instead. Meowth, James and Jessie jump into the melee as Ash's friends drag him away. Ash notices his hat and Pikachu runs for it. Primeape beats Team Rocket and gets between Pikachu and Ash's hat. Pikachu tries not to look at Primeape in the eye, but he eventually does, nervously backing away as it reclaims the hat. Pikachu attacks with Thunder Shock, but it only makes Primeape angrier. Brock thinks Primeape is scared of them and approaches it, but it pounds on Brock and sends him flying. Primeape continues to Thrash and runs after Ash and Misty. They run away as Team Rocket pursues them as well. Ash and Misty split up, Primeape following Ash. Brock catches up with Misty as they decide to catch up to Ash.
Ash keeps running as Primeape destroys boulders in its path. Meanwhile, Team Rocket sets up a pit trap in Ash's path. They see dust in the distance as Ash and Pikachu plunge in, Primeape managing to stop in time. Koffing releases gas as Ash confronts Team Rocket. Pikachu attacks with Thunder Shock, hurting Team Rocket and Ash. Ash sees Primeape as it jumps in. Ash scrambles out but Primeape jumps in front of him, staring him in the eye. Ash remembers what Oak said and decides to get serious and catch Primeape. Misty insists for Ash to forget it, but Ash wants to face it to get stronger. He sends Squirtle to fire Water Gun, but it makes Primeape angrier. Ash sends Bulbasaur to use Razor Leaf, but Primeape's punches destroy the leaves. Ash sends Charmander out, using Flamethrower, but Primeape dodges before pounding Charmander with several punches. Primeape is relentless, though Charmander's flame suddenly grows; the Pokédex points out that it is the move Rage. Charmander takes more punches before biting Primeape's fist, but it is tossed aside. Charmander fires another Flamethrower and Pikachu jumps and grabs the hat, escaping before the attack roasts Primeape. Primeape slumps as Ash tosses the Poké Ball. Primeape goes inside as the Ball rattles. It stops, the catch an apparent success. The Ball rattles again, but it stops a second time, this time inert as Ash claims the Ball holding his Primeape.
Pikachu gives Ash his hat back as Team Rocket climbs out of the hole. They wonder where Primeape is as Ash throws the ball in. Primeape jumps out and pounds Team Rocket, sending them flying. Ash commends Primeape, but it gives Ash a black eye. Ash recalls his Charmander and Primeape. Pikachu points over the cliff as they see Celadon City. Misty notes that Primeape's chase sped up the trip. Ash puts his hat on, as he is excited to get the next Badge. Meanwhile, Team Rocket lands in a canyon full of angry Primeape, who go on to attack them.
In Mystery at the Lighthouse, Professor Oak tells Ash that Garycaught 45 Pokémon. However, in this episode, Oak tells Ash that Gary caught 30 Pokémon. It should be noted that this was also present in the Japanese version.
The writing on the Poké Ball in the advertisement is spelled "POCKEMON LEAG". This was not corrected in the dub, possibly as it is hard to read anyway. This misspelling of "Pokémon" as "Pockemon" is likely due to the fact that at the time of this episode's production (1997) there were no concrete plans for Pokémon's appearance to be international, and thus no standard romanization. Compare: ポケモン/ポケットモンスター (Pokémon/Pocketto Monsutā).
When Ash reaches for his hat after climbing the tree, the hat is facing backward on Mankey's head. However, in the next shot where Ash is knocked to the ground, the hat is facing forward.
In the same shot, Ash's shoes are completely black.
When James kicks Mankey, he kicks Mankey away from him. In the next shot, however, Mankey is behind Team Rocket.
Mankey is also seen without Ash's hat on his head when he begins to evolve. However, after evolving into Primeape, Ash's hat is suddenly on its head again.
The half-focused eyes on Misty's face appear twice when she comments on Ash's "Donut Pokémon": both before and after her lips start moving.
When Ash throws his Poké Ball to catch Primeape, it lands and wobbles upside down. The next shot after that, it is right side up. Ash's Poké Ball continues to wobble in this position until Primeape is caught.
When Ash gets beat up by Primeape after catching it, he commands Charmander and Primeape to return to their respective Poké Balls. At that moment, Pikachu disappears as well, but reappears just a few seconds later in the next scene overlooking Celadon City.
When Ash and his friends are overlooking Celadon City, Ash's hat is completely red.
The Poké Ball with "POCKEMON LEAG" inscribed on it