• English / United States: Ash's Tranquill
• Japanese / Japan: サトシのハトーボー
• Japanese (Romanized) / Japan: Satoshi no Hatoboh
• Japanese (Trans) / Japan: Satoshi's Hatoboh

Ash's Tranquill evolved from Ash's Pidove on the day that Ash Ketchum was helping round up all the Fushide that had invaded Hiun City. Ash's Pidove had been working hard the entire day and it could tell that its strength was increasing which then caused it to evolve.

Gym Battle against Skyla

In Skyla air battle simulation, Ash's Tranquill was matched up against Skyla's Unfezant and since her Pokémon was the highest evolved form, she determined that her Pokémon would be the winner in that match-up. In the actual gym battle, Ash's Tranquill was matched up first against Skyla's Swoobat who had just defeated Ash's Krokorok. At first, Skyla's Swoobat and Ash's Tranquill moves seemed to be equally matched but Ash Ketchum realized that they wouldn't loose in a speed battle and a combo of Wing Attack and Air Cutter knocked out Skyla's Swoobat. Skyla pitted its loss on the fact that her Swoobat had already gone through one match, so it had a disadvantage.

Ash's Tranquill was then matched up against Skyla's Unfezant which was the match-up that Skyla had predicted that her Unfezant would win. Skyla's Unfezant proved to be stronger and faster than Ash's Tranquill, so Ash Ketchum recalled it and set out Pikachu. Pikachu ended up knocking out Skyla's Unfezant but it got knocked out by Skyla's Swanna.

After Ash's Tranquill replaced Pikachu in the final match-up in the gym battle, Ash's Tranquill was overpowered by Skyla's Swanna's Hurricane and was knocked down hard to the ground. Ash's Tranquill then evolved into Ash's Unfezant and proved it was stronger and faster than Skyla's Swanna.