Movie
Description
Professor Samuel Oak stands as a preeminent Pokémon researcher based in Pallet Town. His groundbreaking work focuses on human-Pokémon interactions, leading to the creation of essential tools like the comprehensive digital Pokédex encyclopedia.

Born into a prominent Pallet Town family, Oak has two brothers: the town's mayor and postmaster. His grandfather gained renown as the area's first notable Pokémon Trainer. Oak himself displayed exceptional academic talent, publishing significant Pokémon research by age 20 and becoming a professor at Celadon University by 25. Childhood visits to Pokémon fossil museums sparked his passion, leading him to sketch Pokémon and aspire to be a Pokémon Watcher. During his youth, a warning about the "Voice of the Forest" from a woman named Towa preceded his encounter with Celebi in an Arborville forest. When a poacher attacked Celebi, Oak defended the Mythical Pokémon, resulting in both being teleported 40 years into the future where he met Ash Ketchum. After thwarting the poacher and witnessing Celebi's restoration by other Celebi across time, Oak returned to his own era.

Personality-wise, Oak exhibits occasional forgetfulness and enjoys composing senryū about Pokémon. He shares a close, long-standing friendship with Delia Ketchum, Ash's mother, and has known Ash since childhood, running activities like a Pokémon summer camp Ash attended. His laboratory houses numerous Pokémon, including starter Pokémon Bulbasaur, Charmander, and Squirtle, which he provides to new Trainers. He experiences recurring comedic discomfort from Ash's overly affectionate Muk.

In "Pokémon the Movie: I Choose You!", Oak appears on a televised broadcast describing the three starter Pokémon. When Ash arrives late, only Pikachu remains. Oak warns Ash about Pikachu's rebellious nature and unsuitability for beginners but provides Pikachu along with a Pokédex and six Poké Balls. Later, when Ash contacts him from Viridian City reporting an unidentified golden bird Pokémon (Ho-Oh), Oak dismisses the sighting, noting many Trainers have searched unsuccessfully for that Pokémon throughout their lives.

Throughout Ash's journeys, Oak cares for Pokémon Ash captures beyond his active team, storing them at his laboratory. He monitors Ash's progress, occasionally comparing it unfavorably to his grandson Gary's early achievements in Pokémon collection. He facilitates Ash's travels, enabling participation in leagues like the Orange League and Orange Islands, and later requests Ash transport the mysterious GS Ball to researcher Kurt in Johto. Oak mentors other professors, including Professor Elm, and collaborates internationally with researchers like Professor Juniper in Unova and Professor Kukui in Alola. His personal Pokémon team includes a Pidgey (used to demonstrate size doesn't determine strength), a powerful Dragonite battler, and a Rotom captured during research on form changes.