Abandoned as a kitten, Meowth survived on Hollywood's streets. He joined a gang of feral Meowth led by a Persian, stealing food and scavenging in trash. His life changed upon meeting a female Meowth named Meowzie; smitten, he learned she preferred humans. To impress her, Meowth dedicated intense effort to emulate humans. He taught himself to walk upright and mastered human speech, adopting a distinct New York accent. This transformation backfired when Meowzie rejected him as unnatural, deepening his heartbreak. The word "Rocket," the first human word he understood, drew him to join Team Rocket.

Within Team Rocket, Meowth initially hoped to become Giovanni's favored "top cat," but Giovanni's Persian overshadowed him, fueling lasting resentment toward the species. Assigned to Jessie and James, Meowth serves as their strategist and technician. He designs machinery, formulates plans to steal valuable Pokémon—especially Ash Ketchum's Pikachu—and operates their Meowth-themed transport like hot-air balloons. His ability to speak human language and translate Pokémon communication makes him vital for coordinating schemes and understanding targets. Though he sometimes considers himself the leader, he typically defers to Jessie's assertiveness and maintains loyalty to both teammates through repeated failures. Despite frequent bickering, he views Jessie and James as his only true friends.

Meowth's self-taught human traits came at a cost: the mental effort expended learning speech and bipedal movement left him unable to master his species' signature coin-generating move, Pay Day. This deficiency often renders him ineffective in direct combat, though he occasionally demonstrates formidable prowess when deeply motivated. Ambitions to regain Giovanni's favor manifest in elaborate, often unrealistic fantasies about rewards for capturing Pikachu. Despite his antagonistic role, he exhibits compassion, particularly toward abandoned or mistreated Pokémon, stemming from his own experiences. He reassured Ash's abandoned Chimchar about finding a better life and empathized with pirate Pokémon seeking revenge after being discarded by trainers.

Meowth remains a wild Pokémon by choice, refusing capture in a Poké Ball despite occasional interest in Luxury Balls. He has not evolved into Persian, influenced by his disdain for Giovanni's Persian and unresolved insecurities. Throughout his travels, he displays sporadic romantic interests in Pokémon like May's Skitty, a Sinnoh Glameow, and various Eeveelutions, though none supplant his lingering attachment to Meowzie. His dynamic with Pikachu is complex; while archenemies, Meowth acknowledged they could have been friends under different circumstances. He occasionally collaborates with Pikachu when necessary, though mutual distrust persists from past betrayals.