Although lacking a physical body, Spiritomb projects its appearance out of a small rock called the Odd Keystone. The rock is trapezoidal in shape and has two small dots. There is a crack running down the middle, splitting in two near the bottom. The crack in combination with the two dots appears to form a frowning face. Spiritomb's projected appearance is an ethereal composition of swirling purple fog. Its face is set in the middle of the fog and contains green, crescent eyes that are connected to its jagged mouth. Its pupils are composed of a spiral and it is sometimes only seen with one. Swirling around its face are green orbs with yellow centers.
Spiritomb is formed by the collection of 108 spirits being trapped in an Odd Keystone due to misdeeds. Some Spiritomb are up to 500 years old.
Years ago, an evil Spiritomb was causing destruction through the village. Until one day a man with a Pikachu simply known as the Aura Guardian arrived to confront the evil Pokémon. After a long and grueling battle, Spiritomb was defeated and was sealed inside it's own Odd Keystone. To prevent Spritomb from causing anymore destruction, the villager created a Hollowed Stone Tower and placed the Odd Keystone in the Tower.
Spiritomb remained in the Tower, for many, many years. Until one day, when Ash and Dawn were battling each other to test their newly traded Pokémon. Dawn's Aipom used Focus Punch on Ash's Buizel, but she missed. The Focus Punch ended up hitting the Hollowed Stone Tower, which destroyed it. When that happened, Spiritomb was released. Spiritomb attacked the group with a powerful Shadow Ball. Ash's Buizel attacked Spiritomb with Water Gun, but the Water Gun went straight through Spiritomb, dealing no damage. Spiritomb then processed with a Shadow Ball directly at Buizel, knocking him out. After which Spiritomb flew away.