Chatler has been with Pearl since before the start of the series. Chatler first appeared in Stagestruck Starly, performing in Diamond and Pearl's comedy routine in Jubilife City. During the skit, Pearl has Chatler blow the grass away, however, when Chatler did so, it revealed Diamond and Lax's lazy selves, which made both Pearl and Chatler mad. Despite ruining the act, the audience found it funny, allowing Diamond and Pearl to win the special prize. Later the two are attacked by a group of Starly and Chatler helps fend them off alongside the other Pokémon.
In Problematic Probopass & Mad Magnezone II, Chatler fought Cyrus after Cyrus had Magnezone use its magnetic powers to draw out the camera hidden inside Lax's fur. Chatler quickly flew by and grabbed the camera but was subdued by Probopass's Gravity. Chatler's Trainer, unable to do a thing in said state, asks for Cyrus to lift the attack. This allowed for Chatler to gain his mobility and crush the camera Cyrus used to capture the images of the ruin paintings.
In Winning Over Wingull, Chatler sensed two violent Wingull approaching and warned Pearl about the danger. Despite the warning the two Wingull hit Pearl and cause him to lose his balance. Angered, Pearl has Chatler attack the two with Pluck. Despite the speed advantage Chatler is quickly put at a disadvantage due to fighting two of them and their constant use of Roost. Because of this Pearl sends Chimler in to battle as well until he notices an injured Wingull near him.
In Outwitting Octillery, Chatler works alongside his team to reach the middle of Lake Valor in an attempt to find Azelf. Halfway across the lake they get attacked by Saturn's Octillery, who uses Octazooka to destroy their raft. Saturn shows up on a UFO-like vessel and grabs Pearl while demanding to know why he was heading for the island at the middle of the lake while Chatler, Chimler, and Rayler desperately try to free him. A few minutes later the Galatic Bomb goes off, with its target revealed to be Lake Valor. Pearl and Saturn witness Azelf reveal itself and Saturn and his grunts begin trying to capture it. Pearl and his team attempt to stop them but are overwhelmed by the number of opponents and defeated.
In The Final Dimensional Duel XI, Chatler tried to stop Charon from closing the portal to the Distortion World with his machine. Charon quickly uses the machine to control Chatler and have him attack his own Trainer instead. Rotom then shows up in a Proteam Omega toy and destroys the machine.
Personality and characteristics
Like his Trainer, Chatler is quick, impatient, and easily irritable, taking out most of his anger on Diamond's Lax, in a manner similar to how Pearl behaves towards Diamond. He is a fairly strong fighter and is occasionally used for battling, though Pearl tends to use Chimler over him. Pearl occasionally uses him to listen in on conversations and repeat them.