In Primeape Goes Bananas, Ash learned that Gary had already caught 30 Pokémon, he aspired to catch more for himself. Soon afterward on Route 7, a friendly wildMankey ate some of Brock's food. Ash took this opportunity to try to catch the Pokémon, but the Poké Ball failed, instead catching a rice ball. Mankey was angered and chased the group, beat up Ash, and stole his hat. Mankey gleefully teased Ash as the young Trainer fumed over having his beloved cap stolen. Team Rocket decided this was the perfect opportunity to plot how to capture Pikachu, with Mankey approaching the trio out of curiosity. James kicked it out of sight and this angered the Mankey so much that it evolved into Primeape. It proceeded to punch Jessie in the face, sending her face-first into a rock, then viciously attacked the other Team Rocket members. After it beat up Brock, chased Ash and Misty down Route 7 and followed Ash into one of Team Rocket's pitfalls, Ash made several attempts to catch the rampaging Primeape, and eventually, his Charmander was finally able to defeat it. Ash caught it and unleashed it upon Team Rocket, where it brutalized them and sent them blasting off into a nest full of wild Primeape.
Ash considered using Primeape in his match against Erika in Pokémon Scent-Sation!. However, after thinking back to Primeape's explosive aggression, he decided not to, as its brutality would most likely have cost him the match.
Primeape and Ash after winning the P1 Grand Prix
In The Punchy Pokémon, after leaving Celadon City, Ash and his friends met a man named Anthony who was training to win the P1 Grand Prix, a tournament for Fighting-type Pokémon. Anthony's daughter, Rebecca, wanted him to stop spending so much time away from home training. Brock and Ash volunteered to enter the tournament to discourage Anthony, with Ash entering Primeape. In the first match against a Machop, Ash saved Primeape from a nasty fall, which caused the usually vicious Pokémon to become closer to Ash. Primeape listened to Ash's instructions and eventually won the tournament. Anthony offered to train Primeape for Ash, with the promise of training it to become a P1 champion, so Ash left Primeape with Anthony. Primeape, unlike the other Pokémon that Ash has given to another Trainer for training, hasn't been seen since, although the narrator in the dub hinted at the end of the episode that it's possible that Primeape would return.
Despite its few appearances, Primeape was naturally very mischievous, but it also showed itself to be particularly irritable. Primeape's short fuse made it prone to explosive outrages and merciless violence. However, Ash saw through this flaw and went on to catch Primeape in the hopes of using its ample energy for battles. Primeape's potential shone through during the P1 Grand Prix event in The Punchy Pokémon, where its athletic prowess and sheer power was able to be utilized. Underneath the explosively violent personality, it had a softer side, which allowed it to bond with Ash.
Ash's Mankey appeared in Clefairy Tale. It was initially a member a larger group of Mankey pursued in a forest by Ash and his Fearow. After Fearow cut the Mankey off and Pikachu attacked them with Thunder Shock, the Mankey panicked and slammed into a Beedrill nest, causing both groups to be attacked by the swarm of angry Poison Bee Pokémon. Later, after finding out that his Mankey was only a Grade D capture, a disappointed Ash started walking around and came across a man who offered him a map of Mt. Moon to find Clefairy. Ash offered the man his Mankey in exchange for the map, only to later find out that the map was false and that he had been scammed.