Ditto's Mysterious Mansion

On their journey through the Kanto region, Ash and his friends seek shelter from the sudden downpour in an abandoned mansion. The house is called "the House of Imitation" and is inhabited by Duplica and her Ditto. She explains Ditto's ability to transform into any Pokémon or person. Duplica also enjoys imitating people. Before Ash can even look around, a second Ash appears before him.