Inkay first appeared while Team Rocket was dining at a café in Lumiose City. As Team Rocket were busy celebrating news from Giovanni, Inkay stole their food and proceeded to eat it from under their table. While Team Rocket were on their balloon, the same Inkay from before approached them when they dropped their sandwich and sprayed ink at them. After Team Rocket cleaned themselves off, James scanned the Inkay to get some details about it and the Team Rocket trio attempted to battle it with Wobbuffet. However, James offered Inkay some food instead as bait. While Inkay was distracted, James threw a Poké Ball at it and caught it, much to the horror of Jessie and Meowth. Inkay was also used to impersonate Ash's Pikachu in an attempt to cause havoc in a town in Heroes - Friends and Faux Alike!.
Since A Conspiracy to Conquer!, Inkay formed a grudge against the evil Malamar who used Hypnosis on it as well as its trainer, Jessie, Pumpkaboo, Ash's friends, Pikachu, Officer Jenny, Wobbuffet, and several Pokémon for its own selfish desires of conquering the world. In Facing the Grand Design!, when everyone was kidnapped by the three evil Malamars except for Clemont and James, it convinced the good Malamar and several other Inkays to fight against the evil Malamars, stop their plans and save their friends from mortal danger. However, during the rescue mission, one of the evil Malamar brainwashed Inkay and forced it to attack everyone. But James managed to save Inkay by breaking it free from the evil Malamar's hypnotic control and Inkay continued the battle to save everyone.
Inkay appears to be a sneaky and mischievous Pokémon, as it was seen stealing food from Team Rocket and then followed them in their balloon. It seems to love food and would often go out of its way to steal it. However, James at one point used this to his advantage to capture Inkay. Despite being very mischievous and being a Pokémon owned by Team Rocket, Inkay holds a deep grudge against the evil Malamar it encountered during its travels and would do anything to stop it from fulfilling its dark plans of destroying the world.