Choose It or Lose It (Japanese: ライバル対決！ＶＳマサムネ！！ Rival Confrontation! VS Morrison!!) is the 38th episode of Pokémon: Advanced Battle.
The judge is about to announce Morrison's defeat, but Ash tells him Morrison needs time to think. Ash tells him to snap out of it, so Morrison brings Growlithe. Corphish uses BubbleBeam, but Growlithe dodges. Corphish tries again, but Growlithe dodges using Agility. One attack pushes Growlithe on an ice spike, so Corphish uses Crabhammer, defeating Growlithe. Ash yells at Morrison, as to why does not he battle better. Morrison denies and apologizes to Growlithe for letting it down, so Growlithe accepts by licking his face. Morrison regains his spirit and tells Ash if he wants a battle, he'll give it to him.
Morrison sends Swampert. Corphish uses Crabhammer, so Swampert counters with Focus Punch, so the nobody dealt damage. Corphish uses Bubble Beam, so Swampert counters with Hydro Pump. They clash again with Focus Punch and Crabhammer and both Pokémon are defeated. Since Morrison lost three Pokémon, a pause is made. Later, Ash is determined to beat Morrison. Morrison comes to apologize to Ash for the behavior before. Ash is taken back, so Morrison yells at him and tells that he was not as competitive as before, but now knows what victory means, at the point where Ash yelled at him at the stadium to realize what means to win.
The battle field has been changed to grass. Ash sends Pikachu and Morrison his Steelix. Steelix starts with DragonBreath, but Pikachu uses Quick Attack to dodge and attack him. However, Steelix uses Iron Tail before Pikachu hits it. Steelix digs and hits Pikachu. Pikachu uses Iron Tail, but misses when Steelix digs again. Steelix comes out, so Pikachu uses Quick Attack to hit it. Pikachu and Steelix use Iron Tail on one another, but Pikachu is knocked out and defeated. Team Rocket still sell food, with more business than ever.
Ash sends Torkoal. Steelix uses DragonBreath, but Torkoal protects itself with Iron Defense. Torkoal comes out and uses Overheat, so Steelix counters with DragonBreath, but Overheat is much more powerful and hits Steelix. Torkoal attacks with Flamethrower and Steelix uses DragonBreath, so an explosion is made. Steelix digs, so Torkoal protects itself with Iron Defense, but with no effect when Steelix comes out. Steelix uses DragonBreath, defeating Torkoal. Ash sends Grovyle to the fight. Steelix uses Iron Tail, but Grovyle dodges and uses Bullet Seed, but misses when Steelix digs.
Steelix comes out, but Grovyle evaded. Steelix uses DragonBreath, but Grovyle charges with Leaf Blade, negating the attack and defeating Steelix. Morrison sends Gligar, so Grovyle uses Quick Attack, though Gligar evades. Gligar follows Grovyle and uses Steel Wing, but Grovyle hides in the grass. Grovyle comes out and uses Bullet Seed, hitting Gligar. Gligar uses Steel Wing again, so Grovyle hides in the grass, but this time, Gligar goes to find Grovyle. Grovyle jumps on Gligar and goes to use Leaf Blade, but Gligar shakes him off. Gligar uses Guillotine, so Grovyle uses Bullet Seed, but Gligar evades and uses Guillotine on Grovyle and sends him to the ground.
Ash sends Swellow. Gligar uses Guillotine, though Swellow uses Double Team. Gligar hits the illusions, so Swellow goes to peck it, but Gligar evades and uses Iron Tail. Swellow uses Quick Attack to dodge the attack, so Gligar uses Hidden Power to hit it. Swellow uses Aerial Ace, so Gligar counters with Steel Wing. Swellow uses Aerial Ace once more and Gligar Steel Wing, until they reach a point where both Pokémon fall down defeated. As the last Pokémon left, Ash sends Glalie and Morrison Metang. Glalie goes to headbutt, so Metang uses Take Down, so Glalie is hurt. Glalie uses Ice Beam, but Metang redirects the attack with Confusion. Metang charges with another Take Down, hurting Glalie.
Glalie uses Ice Beam again, so Metang uses Confusion to redirect the attack. However, Glalie uses Icy Wind to redirect the attack back to Metang, leaving it frozen. Glalie headbutts Metang, so Metang is unfrozen. Metang counter-attacks with Meteor Mash, hitting Glalie. Glalie headbutts while spinning, so Metang uses Meteor Mash. Glalie evades the Meteor Mash and hits Metang, defeating it. Ash wins the battle and proceeds to the next round. Tyson also has his battle - Sceptile fires Solar Beam, hitting Rhydon and defeating it. At the night, Morrison screams for his defeat. Ash comes to thank him for the battle they had. Tyson tells them it is dinner time, so Ash and Morrison race to get to the restaurant.
Meanwhile, Team Rocket gets the treat of their life - their boss was so generous he brought a lot of tasty food. The boss tells them he needs to go on a trip and leaves them in charge until he returns. The screen displays another shocking news - Ash's next opponent is Tyson. Ash and Tyson promise each other a battle they will never forget. Meowth is happy to have a job and sees Ash vs. Tyson, remembering Tyson's Meowth. Meanwhile, Tyson gives his speech to his Pokémon (Sceptile, Metagross, Meowth, Shiftry, Donphan and Hariyama) that they need to give their best to defeat Ash's Pokémon. They begin to practice and Tyson's Meowth is called by Team Rocket's. Team Rocket's Meowth tells Tyson's Meowth that Pikachu is harder to beat than it looks. Tyson's Meowth tells Team Rocket's Meowth he needs not to worry and cuts some branches, showing its power. Meowth calls Tyson's Meowth an amateur and is knocked out by a tree Meowth cut.
Morrison and Ash sleep on the tree. Morrison thinks Ash will be defeated against Tyson. Ash thinks he might be able to beat him, so Morrison goes to sleep, but tells him he will win. The next day, Ash battles Tyson. The grass battlefield comes up and Ash sends Glalie and Tyson his Sceptile. Glalie starts with Ice Beam and Sceptile Solar Beam. The attacks contact and make a huge explosion. Who will win?
- Featured Pokémon: Feebas, Lickitung, Wobbuffet