-Gengar-

Gengar, Gastly, and Haunter were in a haunted castle, and you entered to investigate what had happened to the family who lived there. When you saw a chair at the end of the hallway, the chair started moving on its own toward the kitchen, and you got scared, obviously, because there were three ghost-type Pokémon—Gastly, Haunter, and Gengar—hiding in the walls, and you couldn't see them.