Pokémon Fushigi no Dungeon: Shutsudou Pokémon Kyuujotai Ganbaruzu!

A human wakes up one day to discover that he has become a Squirtle in a world filled with natural disasters, where he meets Charmander and Chikorita of Team Go-Getters, a Pokemon rescue team. Squirtle joins Team Go-Getters for the task of saving Pichu's Brother Pikachu from Skarmory, however Gengar and his Team Meanies decide to interfere.

(Source: Anime News Network)