Pokemon Season 12 - Episode 568 – Get Your Rotom Running!

When Professor Oak finds out that Ash and friends are in Canalave city, he recommends a hotel called the Old Chateau that serves a special dessert called Old Gateau. The group goes to the hotel immediately, but they're sad to see the hotel is closed. When they are about to turn back and leave, the doors open by themselves. The group walks inside, where they see a microwave oven. Ash and Pikachu stare at the mysterious microwave oven, and it suddenly attacks! Ash and his friends get chased around the Chateau by the microwave, which they later find out is a Pokémon called Rotom. The Rotom obtains different guises, such as a refrigerator. Rotom gets defeated and tells them sorry, but it was just trying to play with them. Brock eventually makes the Old Gateau, which Ash and his friends enjoy.