Pheromosa first appear escaping the Ultra Wormhole to the real world at night. It began to steal Z-Crystals from their respective owners. Its first target is Hala. On the next day, Pheromosa also steals the Z-Crystals from Kagetora, Hiroki and Pikala off-screen before going to Team Rocket. It was then, Team Rocket's Meowth fell in love with its feminine appearance, and Pheromosa made him its unwitting pawn, such as luring the other Z-Crystal owners like the Ultra Guardians into their trap. Because of Meowth’s foolishness and naivety to be blindly loyal to Pheromosa, and Pheromosa’s power level on its speed, they become unstoppable, not even an ambush by either Ultra Guardians or Team Rocket works. Once Meowth served his purpose, Pheromosa betrayed Meowth and broke his heart, until Bewear avenge his humility and uses her instinct to counter the Ultra Beast’s hi-speed power, returning the Z-Crystals into their rightful owners. Before Pheromosa awakes while knocked down badly, Rotom-Dex quickly warns Ash to catch it and release it to Ultra Space. Despite Ash manage to capture it, he and his friends feels disappointed that Pheromosa’s defeat was not by them but Bewear. Upon being released back to Ultra Space, Pheromosa will remember its humiliating defeat by the Ultra Guardians and Team Rocket, although they figure it will soon change.
None of Pheromosa's moves are known.