Cheryl's Mothim (Japanese: モミのガーメイルMomi's Gamale) is a Pokémon owned by Cheryl.
As a Burmy
Mothim first appeared as a wild Burmy when he was lured to a Sweet Honey Tree that Ash's Aipom found. It was then revealed that Cheryl put Honey on that tree to catch a Burmy. When he appeared, Cheryl checked his gender by having her Chansey use Attract on him, which was successful. She battled Burmy with Chansey and after weakening him a bit, Cheryl threw a Poké Ball at him and successfully caught him. After catching Burmy, Cheryl explained how she was a treasure hunter and needed a male Burmy to evolve into a Mothim. She then showed Ash and his friends that she had three Wormadam and explained that she needed a Mothim to assist her in finding the Amber Castle.
Ash volunteered to help Burmy evolve so he sent Turtwig out first to battle him. Despite the type-advantage, Burmy easily bounced off of Turtwig when he tackled him. As Turtwig used Tackle back, it caused Burmy to get thrown back and lost after Turtwig panicked and used Tackle again. Seeing that Turtwig was a little too tough, Pikachu took Turtwig's place in getting Burmy to evolve. Unlike before, Burmy was not able to get sent flying. During the middle of the battle, he got stolen by Team Rocket and they do their own ways of battling to get Burmy to evolve. After a snack break, he took on Wobbuffet, who could not use any damaging moves. Meowth took over and accidentally won. As soon as Ash and his friends arrived, Burmy battled with his full potential. He used the coil-like appendage to wrap up Wobbuffet and squeeze it. He ran to Meowth and tackled him. After using Hidden Power on both Meowth and Wobbuffet, Burmy ended up evolving into Mothim. After evolving, he teamed up with Cheryl's Chansey to defeat Seviper and Carnivine. With Team Rocket defeated, Mothim continued the search for the Amber Castle.
As a Burmy, uncoiling his appendage
Mothim and Cheryl
In The Grass-Type Is Always Greener!, Mothim got sidetracked by the scent of Honey coming from the same tree he was caught on. The next day, Mothim got excited about finding the Amber Castle and while he was calling out to get the group's attention, they ended up with an unpleasant encounter with a Gloom when he dove down. After the Gloom fled, he watched the battle between Gardenia and Ash. When the battle was done, Mothim went with Cheryl when she introduced herself to the Gym Leader, circling around her. Team Rocket arrived, after evading a swarm of Beedrill which evolved from Kakuna earlier, and Mothim was once again taken by Team Rocket even though Brock protected Cheryl from getting caught by them. However, the trio were not successful as Gardenia's Turtwig used Leech Seed on their mecha arm and Mothim was freed. Mothim flew off to some flowers and found a male Combee near one. Mothim and the group then followed him as he was the key to the Amber Castle.
In An Angry Combeenation!, Mothim continued to follow the Combee and lost sight of him after coming across a Pomeg flower. Mothim and the group follow the Pomeg flowers and finally arrived at Amber Castle when they saw a group of Combee there. Mothim and Pikachu both look around for a cave entrance and find one under a waterfall. Inside the cave, he went to a room with blue light coming down from it. When Mothim flew into a tunnel in the wall, he ended up getting lost from the group, but end up getting back together later on. A swarm of Combee who were led by a Vespiquen attack Ash and his friends. Mothim stopped them with Supersonic which confused them and Team Rocket's Pokémon. Continuing on, the group encounter another set of Combee and Mothim once again used Supersonic which revealed the Amber Castle. When Team Rocket came by one last time in the castle, Mothim used Supersonic to prevent them from getting away.
Personality and characteristics
When battling as a Burmy, he showed a lot of confidence, seeming very committed to evolving for his new Trainer. This commitment was further shown while sniffing out the Sweet Honey and finding the Amber Castle. Despite losing his training battles, Burmy was never discouraged and never fearful after being kidnapped by Team Rocket, interacting with Meowth oblivious of any danger he could have been in.