Bailey is the Gym Leader of Greenpine City's Gym, known officially as the Greenpine Gym. He specializes in Grass-type Pokémon. He gives the Nature Badge to trainers who defeat him.
When the player first trying to enter Greenpine City's Gym, Bailey isn't there at the moment. He is doing some researches in Tropic Jungle and Cascade Waterfalls. After finding him in Cascade Waterfalls and trying to catch the rare Cryodro, he returns to the Gym.
After this, He appears as the leader of Greenpine City's Gym. This gym is the sixth to be challenged by the player. Trainers who defeat Bailey will receive the Nature Badge, along with TM103 Leaf Darts.