Dr. Willow

Professor Willow is a Pokémon Professor who appears in the Pokémon GO mobile game. Similar to Professor Birch, he specializes in Pokémon habitats and distribution. Unlike other Professors who directly give Trainers their first Pokémon, Professor Willow gives Trainers their first Poké Balls to capture their first Pokémon.

(Source: Bulbapedia)