From Professor Sycamore, Trevor chose Charizard, as a Charmander, as his starter Pokémon. Unlike Trevor who is shy and cautious, Charmander is very energetic and likes to play chase with other Pokémon. During the events of the Pokémon Summer Camp, Charmander got startled and ran off. Upon encountering the heroes' Pokémon, it used Fire Fang on Chespin, causing him to get burned and doused by Tierno's Squirtle's Water Gun. Trevor ran and caught his Charmander, apologizing to others for the trouble. Later, Trevor sent Charmander to battle Clemont's Chespin. Charmander used Flame Charge, litting Chespin's tail, who extinguished it by laying on the sand.
The following day, Trevor took Charmander through the dark maze to collect a stamp. When Bonnie was gone missing, the teams noticed some footprints; Charmander followed them and illuminated the foggy area. Once they found Bonnie, Trevor had Charmander attack some Drifloon and Drifblim with Flamethrower, causing them to float and allow Ash to jump onto them to save Bonnie. However, when Ash was returning, he nearly fell down, so everyone pulled Clemont's Aipom Arm to pull Ash, Bonnie and Pikachu back up.
On the last day of the Pokémon Summer Camp, before the tournament began, Team Squirtle came to the cooks - who were the Team Rocket Trio - and were told they needed to hand over their Pokémon for health inspection at the Pokémon Center. Tierno gave his Squirtle, Shauna her Bulbasaur and Trevor his Charmander. After some time, Team Squirtle visited the Pokémon Center and were shocked to hear the cooks did not give her the Pokémon. The heroes joined Team Squirtle in finding the missing Pokémon. They found the cooks and Pikachu removed the table cloth, revealing Team Squirtle's Pokémon had been captured and binded by Leech Seed. Team Rocket removed their disguises and attacked with Inkay and Pumpkaboo. Clemont's Bunnelby used Dig, distracting Team Rocket and allowing Froakie to free the Pokémon by using Cut on the vines. Later on, Team Squirtle faced Team Froakie in a three-on-three battle. Charmander started with Flamethrower, a move which Fennekin used as well for collision. Charmander used Flame Burst on Chespin, and due to the secondary effect, the move hit Pikachu as well. After Serena's Fennekin was defeated, Charmander tried to defeat Pikachu with Flamethrower, but was defeated by his Thunderbolt.
Later, Trevor was looking for his Charmeleon near Mt. Molteau. He found Charmeleon and got burned by its Flamethrower, but also found the heroes as well. Ash had a quick battle with Charmeleon, using his Fletchinder. Fletchinder dodged Charmeleon's Fire Spin. Fletchinder blocked Charmeleon's Flamethrower attack with Steel Wing and hit it with Flame Charge. Charmeleon used Dragon Claw and Flamethrower, but missed and got defeated by Fletchinder's Steel Wing. When everyone got to the top of Mt. Molteau, Team Rocket attacked them, so Trevor had Charmeleon use Flamethrower, but was countered by Inkay's Psybeam. Charmeleon also used Flamethrower on Moltres, who was angry, thinking the heroes were allied by Team Rocket, who wanted to catch it. Charmeleon was seen beside Trevor, who was watching a Lairon when Tierno told the heroes that Trevor was supposed to meet up with Tierno and Shauna, but found new Pokémon he was interested in taking pictures of.
Trevor used his newly evolved Charizard in the first round of the Lumiose Conference against Alain and his Charizard. Charizard started off by using Fire Spin but Alain's Charizard was able to dodge the attack. Alain's Charizard flew up, using Flamethrower, and Trevor's Charizard blocked the attack with Dragon Claw. Trevor then used his Key Stone and Charizard, with its Mega Stone on its tail, Mega Evolved into Mega Charizard Y. Mega Charizard Y activated its ability, Drought, and used Heat Wave. However, Alain's Charizard slammed its tail on the water, using the water to block Heat Wave. Mega Charizard Y used Dragon Tail but Alain's Charizard flew up, dodging the attack. Alain Mega Evolved his Charizard into Mega Charizard X and it used Flamethrower while Trevor's Mega Charizard used Fire Spin. The two attacks collided, creating some smoke, and Trevor's Mega Charizard used the smoke to approach Alain's Mega Charizard in the air. Alain, however, saw what it was doing and ordered his Mega Charizard to use Flamethrower towards Trevor's Mega Charizard. The latter got hit and landed on the ground, which resulted of getting knocked out. A part of this battle was shown in a TV show, hosted by Malva. Meanwhile, Alain battled well and even advanced to the semifinals. Sawyer was also watching the video of this battle before the finals and took notes about the battle strategies other people were using.
Due to chaos raging in Lumiose City, Trevor sent Charizard to help him protect and escort the citizens to safety. Trevor's Charizard was with its trainer at a Pokémon Center, where Trevor watched the broadcast about the Giant Rock.
Ash remembered Trevor and his Charizard, as Charmeleon, witnessing Fletchinder's evolution when he was reflecting back on his journey.
- ^ XY038: Summer of Discovery!
- ^ XY039: Day Three Blockbusters!
- ^ XY040: Foggy Pokémon Orienteering!
- ^ XY041: Battling Into the Hall of Fame!
- ^ XY086: A Legendary Photo Op!
- ^ XY090: Tag Team Battle Inspiration!
- ^ XY125: A League of His Own!
- ^ XY126: Valuable Experience for All!
- ^ XY129: Kalos League Passion with a Certain Flare!
- ^ XY132: A Towering Takeover!
- ^ XY135: Rocking Kalos Defenses!
- ^ XY136: Forming a More Perfect Union!
- ^ XY140: Till We Compete Again!