|First Appearance||Paper Mario: The Thousand-Year Door and Mario Party XD Seven U|
| Boo Troop|
In McBoo's Mansion, King Boo brainwashed some Boos of Bowser's Koopa Troop to form a Dark Troop. Haunty Mole, a member of this troop, later took over the whole troop and betrayed King Boo. McBoo and friends had to stop the Dark Troop. The Dark Troop includes Dark Boos as common troopers.
Dark Boos in New Super Mario Bros. Omega worked different than other Boos, Boolines or other ghosts. They actually do the inverse of what Boos normally do. Dark Boos approach when Mario faces them, while Boos do that when Mario turns back from those. So Dark Boos will not move when turning back from him. Dark Boos mainly appear in Ghost Houses of later worlds. Dark Boos had in this game glowing eyes, so they actually work as a flashlight in darkness.
|Dark Boo's Stats|
|Location|| Vortex Mansion |
|Items|| 2 Refreshing Herbs or |
a 1-Up Super
Dark Boos appear once again in Mario & Luigi: Rivals Quest as enemies in the locations Vortex Mansion and The Colosseum. They do the same as the Boos in overworld and in-battle, respectively. The only differences is that they're stronger and faster.
Their look is the same as the other games, being purple, with a blue mouth and tongue, and glowing yellow eyes. They also can make dizzy status ailments rarely times.