White Luigi is a character that first appeared in Luigi's Mansion 4: Haunted Dreams. His model is identical to Luigi's, but is white and has white matter surrounding him. Also, he has a high-pitched voice. If Luigi enters a mansion that is being haunted by a White Spirit, White Luigi will appear and will challenge Luigi to a race for the level's Power Star. After bypassing certain obstacles, Luigi will beat White Luigi and will earn the Power Star.
Note that if the player takes control of Mario, White Luigi will be replaced by White Mario, who is not as fast as White Luigi, but can utilise shortcuts and performs a lot of long jumps, which results in White Mario being more difficult to beat than White Luigi.
In Luigi's Mansion 5: Curse of the Mansion, similar enemies known as White Clones, or doppelgangers appear. White Clones' models are slighty different than White Luigi's model, and unlike White Luigi, can mimic every of his performed moves. They can also spawn more of themselves after an amount of time. Additionally, they will try to catch up with Luigi and if he touches them, he loses one health region.
White Luigi and White Mario reappear in Luigi's Mansion 6: U Are Doomed!!. They are once again appearing in Speed Race Spirit missions.