Nariya Ookido

Samson Oak is a Pokémon researcher in Alola. He studies the regional variants of the region. He is a cousin of Professor Oak, with whom he shares a striking resemblance.

In the anime, Samson appeared in Alola to New Adventure!. He is the principal of the Pokémon School and enjoys making puns using the names of Pokémon (while usually doing a visual impression too).

(Source: Bulbapedia)