Mega-Mega Meowth Madness! (Japanese: ハリマロンVSメガメガニャース！！ Chespin VS Mega Mega Meowth!!) is the 10th episode of Pokémon the Series: XY.
Before heading to Cyllage City, the group decides to stop by Sycamore's lab. Team Rocket decides to kidnap Professor Sycamore, as well as Serena and Bonnie, to pry the professor's mind for the secrets behind Mega Evolution, while Ash and Clemont have to deal with a gluttonous little Chespin with a penchant for macarons.
When Ash and Clemont go save Professor Sycamore, Bonnie and Serena, Team Rocket spotted Chespin trying to get the Macarons they try to grab it but it was too fast that they couldn't. When all of them escaped from the place, they all heard a noise coming out from the shed. They saw a big Meowth robot and they all ran as fast as they could. Everyone managed to run fast except for Chespin who was holding onto the Macarons. When Chespin tripped over a rock all the Macarons fell out of the basket. While Chespin was picking them up and putting them back in the basket he was about to get squashed but just in time Clemont grabbed onto Chespin and saved him from getting run over. Since Clemont rolled on his shoulder to save Chespin, he showed an expression that it hurt. Chespin who saw that decided to give Clemont a Macaron. After that Clemont and Chespin went back with the gang and won against Team Rocket. Then Clemont gave Chespin Macarons and he was about to eat it until Chespin decided to give everybody one.
When Ash, Serena, Bonnie and Clemont was going to go back on the road, Bonnie saw Chespin staring at her brother. Clemont was about to say goodbye until Chespin shouted out he wanted to go with them. Clemont asked Professor Sycamore's permission, who gave Chespin to Clemont. Now that everything has settled down they all went towards the next town Cyllage city for Ash's next/second gym battle.
- "Who's that Pokemon?": Chespin (US)
- "Pokemon Quiz": Chespin (JP)
- Blaziken Mask is revealed to be Meyer, Clemont and Bonnie's dad.
- During the explosion of Mega Meowth, Chespin's visible arm is lighter than usual.