Ash's newly caught Treecko may be a bit standoff-ish, but the little green Pokémon is quite a fighter. When Team Rocket sees Treecko knocked down and hurt by a Seviper, they decide that they must have that Seviper. Jessie is very impressed with its "sneaky, snaky ways." Meanwhile, Treecko escapes from the Pokémon Center where Ash brought it to recover. When the gang finds Treecko, it is practicing its attack moves. Again and again, Treecko jumps from the top of a waterfall and tries to break a rock at the bottom with its tail. Ash is very impressed with the rigor of its training. All of Treecko's hard work appears to have paid off—when Team Rocket attacks and catches Pikachu with the help of their new Seviper, Treecko is able to save the day.
Ash, Brock, May and Max stop to make a lunch break. May, Ash and Brock call out their Pokémon as well to eat - Treecko, Taillow, Torchic and Forretress appear, though all stare at the Treecko. Treecko climbs on the nearest tree, takes a branch and spends time alone.
As the gang eats the food, Ash still ties to invite his Treecko to eat. Treecko then spots moving in the bushes. It is revealed to be a Seviper, who then places a tail so that May's Torchic falls. The Torchic loses its apple, so it searches for it. It finds it, but the Seviper eats it. Seviper prepares to attack, but Treecko then throws a branch between them. Treecko attacks, but Seviper instead attacks May's Torchic! The gang arrives, ordering their Pokémon to attack the Seviper. However, Seviper uses Haze to dampen everyone's sight. Treecko spots a nearby tree, climbs it, attacks the Seviper and frees Torchic. The Seviper is angry and uses Poison Tail on Treecko. However, Taillow and Forretress help Treecko by attacking the Seviper. Pikachu attacks with Thunderbolt, making the Seviper leave everyone.
After the battle, Treecko is severely injured, so the gang leaves to the nearest Pokémon Center. Team Rocket is watching them, so they agree to capture the Seviper. The gang rushes to the Pokémon Center, while the Seviper is eating more and more of other Pokémon's apples. Team Rocket sets up a trap, so that when Seviper goes to eat the fruit from the basket, it would fall into a hole. However, the Seviper notices something is wrong, so it takes the basket with its tail. Team Rokcet is furious, but fall into their own hole.
James and Meowth then capture the Seviper using the net. Unfortunately for them, the Seviper then bites the net, setting itself free. However, Jessie is more and more tempted to catch it! Jessie, James and Meowth then have lunch, but when they reach for the last rice ball, they fight for it, but it falls into a nearby river. Jessie saved the last one for herself, but the Seviper eats it before she does. Jessie is mad, so she brings her Wobbuffet. However, James states that Wobbuffet can only use Counter, so Jessie calls him back. Jessie throws Meowth to attack, but Mewoth is given a wrong command, so he is being thrown away by Seviper's tail. Jessie is thrown back and drops her last rice ball. Before the Seviper eats it, Jessie puts her hair to Seviper's mouth, cutting it. Jessie then outrages, making James, Meowth and even Seviper scared.
Jessie then attacks the Seviper, scratching, kicking and battling with it until it is defeated. Before she makes the finishing move, Jessie hears that she should capture it, so she throws the Poké Ball at Seviper. At the Pokémon Center, Nurse Joy states that Treecko is going to be fine. May wonders if this Nurse Joy is younger sister of the one in Oldale Town, but Brock denies it, confusing May with his long description. Nurse Joy's Chansey appears, telling Nurse Joy that Treecko escaped the Pokémon Center. Max spots that Treecko left his bandages and has gone to the nearby hill. Treecko is shown to jump on a rock from a waterfall. Treecko bounces on the rock on his tail and falls into the water. Brock explains that Treecko trains because he lost the battle with Seviper. After being bruised a bit from unsuccessful leaps, Treecko begins to turn itself while falling in the air and manages to crush the rock.
Ash and Pikachu try to rush to congratulate Treecko, but Pikachu is being taken by Team Rocket. They encase Pikachu, for the casing does not conduct electricity. Ash brings his Taillow, while James sends his Cacnea out. Cacnea attacks, but Taillow evades. Jessie announces to bring their newest Pokémon, so she brings Seviper out to fight! Treecko enters the fight, just before Ash convinces him that Ash and others are with him during the fight.
Jessie orders Seviper to attack with Poison Tail, but Treecko uses Quick Attack to dodge. Treecko attacks the Seviper with Pound, so Seviper uses Poison Attack again. Treecko evades the attack, spins himself and attacks Seviper with his tail (as like the training near the waterfall). Treecko gets out of the fight, so Pikachu blasts Team Rocket off. Treecko is pleased by the experience, so Ash and Pikachu shake his tail, as a token of friendship.
- The Who's that Pokémon? of this episode is Gligar.
- Jessie:"AHHHHHHH! Not my hair! My flowing hair is my trademark! Now I'm really mad! You just made a big mistake Seviper!!!"
Seviper is scared.
James: "Poor Seviper."
Meowth: "It knows not what it's done."
Jessie goes on the warpath and claws Seviper.
Meowth: "That's her Fury Swipes attack."
James: "Emphasis on Fury."
Jessie kicks Seviper down.
James: "That's her special Megaton Kick."
Meowth: "And highly effective."
Seviper Faints. Jessie gabs it by the neck.
Jessie: "You rice ball stealing, long-hair chomping-"
James: "Wait, wait!"
Meowth: "Easy on the merchandise! Catch it!"
Jessie: "Catch? Oh, of course, that's just what I was about to do."
Meowth: "That was a close one."