During the Gourgeist Festival, Prince Pumpkaboo, who is a small-sized Pumpkaboo, fell in love with Jessie's super-sized Pumpkaboo. If Jessie and Count Pumpka wanted to make Prince Pumpkaboo happy, they settled in a trade in exchange for Count Pumpka's Mawile. After they traded their Pokémon, Jessie's Pumpkaboo inexplicably evolved into a Gourgeist since the trade triggered Pumpkaboo's evolution. Prince Pumpkaboo was surprised at Gourgeist's new form and he immediately lost interest in it.
None of Prince Pumpkaboo's moves are known.
Todd Garbeil (English)