Professeur Chen, internationally recognized as Professor Samuel Oak, is a celebrated Pokémon researcher based in Pallet Town, Kanto. Renowned for guiding fledgling trainers, he supplies their first partner Pokémon—Bulbasaur, Charmander, Squirtle, Pikachu, or Eevee—and equips them with a Pokédex to catalog species. In *Pokémon Evolutions* episode "The Discovery," he coordinates trainers to finalize the Pokédex. After Green (Blue) admits defeat in completing the task solo, Chen discloses that collective efforts from Pallet Town’s trainers achieved success. He later receives an alert about a newly identified metallic Pokémon, signaling ongoing discoveries, though his protégés have already departed.

A former Pokémon League Champion, Chen triumphed over his rival Agatha in the finals during his youth. Their contentious history resurfaces in games, where Agatha mocks his transition from battling to research. Unused Generation I data suggests he was designed as a post-game challenger, wielding high-level evolved starters.

Across core game titles, Chen upgrades trainers’ Pokédexes and distributes critical tools like the National Pokédex. His Pallet Town laboratory features specialized habitats for Pokémon study and safeguards trainers’ stored companions, mirrored in the anime’s depiction of Ash’s inactive team. Spin-off roles include evaluating Todd Snap’s photography in *Pokémon Snap* and partnering with Mew or Nidorino during *Pokémon Masters EX* events.

In the *Pocket Monsters Special* manga, he competes incognito as "Dr. C," deploying tactical strategies with Fearow and Dodrio. His teachings emphasize collaborative research and the bond between trainers and Pokémon, echoing in-game dialogues that stress trust as foundational to battles.

Family includes grandson Blue, granddaughter Daisy, and cousin Samson Oak (*Pokémon Sun and Moon*). Lab aides like Tracey assist his studies and public endeavors, including a radio program co-hosted with DJ Mary.