Chimler, as a Chimchar, seemed to be very lazy; he could usually be seen resting on a chair or bed and dangling off of his Trainer's arm at times. When not used in battle, Chimler would make great use of his Ember technique which could be used to melt glass or metal so they can get into various places. Chimler also seems to be very ticklish, especially when he comes in contact with grass.
In battle, Chimler proved to be a powerful Pokémon, strong enough to defeat many opponents such as Maylene's Riolu.
Chimler is first seen when Platinum sends him and Tru out of their Poké Balls and instructs them to give a Pokédex to the two men in scarves that would be arriving soon. Seeing two young boys that matched the description, Chimler picks Pearl as his Trainer while Tru picks Diamond as his. After this, they are attacked by a flock of wild Starly and are forced to fight them off, taking them over thirty minutes to do so.
Later, whilst resting in a hotel, Pearl decides to name the Chimp Pokémon "Chimler" and uses him to battle a crowd of rampaging Bidoof.
While Platinum trains for her upcoming Oreburgh Gym battle, Chimler, along with the rest of Pearl and Diamond's Pokémon, are used to help her hone her skills. Suddenly, during a training session, Chimler, Tru, and Piplup evolve into a Monferno, Grotle, and Prinplup, respectively.
In Veilstone City, Chimler, when using a newly-bought Zoom Lens to improve his accuracy, accidentally throws an Ember in the wrong direction and nearly hits the Gym Leader, Maylene. After a misunderstanding, Maylene assumes Chimler belongs to Platinum and wants to see him in their upcoming Gym battle. Later, at the Veilstone Gym, Chimler is used to battle Maylene's Riolu and, after tough battle, manages to defeat it using the skills Platinum gained by playing in the slots.
Later, when going to receive Platinum's missing Pokédex, Pearl is separated from Platinum and meets up with Diamond who was running away from Team Galactic. Chimler, Chatler, Tru, and Lax are all used along with Paka and Uji's Burmy and Buizel to battle Team Galactic. As they battle through the hordes of Staravia and Skuntank, Chimler and Tru suddenly evolve into their final stages, Infernape and Torterra, respectively.
When Pearl traveled to Lake Valor to protect Azelf from Team Galactic, he ended up in the Fuego Ironworks. When Pearl found himself attacked by some of Team Galactic's Magby, he used Chimler and Chatler to fend them off. After Rayler joins their group, Chimler and Chatler welcome their new teammate.
After arriving in Lake Valor, Chimler used his flames to propel Pearl to the Lake before they were attacked by Saturn of Team Galactic. After failing to protect the Lake from being blown up, Chimler attempted to protect Azelf by fighting off Saturn's forces but was defeated.
Chimler was used during the final battle against Cyrus and his controlled Dialga and Palkia on the Spear Pillar. Along with all of and Pearl and Diamond's Pokémon, Chimler fired an attacked that when combined, freed Dialga and Palkia from Cyrus's control, allowing them to defeat him once and for all.
| Using Ember
| A † shows that the move was used recently, unless all moves fit this case or there are fewer than five known moves.