Jessie was asked to trade
Jessie's Pumpkaboo so that the prince could wed her. Despite initial hesitation,
Jessie agreed and traded her Bakeccha for
Pumpka's Kucheat because he told her that it is a Pokémon reported to mega evolve. During the trade process,
Jessie's Pumpkaboo evolved into
Jessie's Gourgeist.
Pumpka then realized that Pumpjin is a trade evolution and the prince liked the way Bakeccha looked better so the trade was nullified and
Pumpka's Mawile stayed in his possession.