Red Boo

Red Boos (also known as Pink Boos, because of their coloration) are a light red or pink colored sub-species of Boos. They are treated and behave similarly to white Boos, with the only difference being their coloration in most depictions. Red Boos also come in a crowned variety.

Super Mario Bros. Deluxe
Red Boos make their first appearance in the "You vs. Boo" feature of Super Mario Bros. Deluxe, in which they were the second-fastest type of Boos (only the Black Boos were faster).

Mario Party series
In Mario Party 4, Red Boos are mainly featured on the board Boo's Haunted Bash. On that board, Red Boos can give a player a ride on the Mystery Train. In later Mario Party games, they served no role other than stealing coins or stars from other players or being featured in various mini-games, such as the Ghost in the Hall mini-game in Mario Party 7. In Mario Party 5, Red Boos appeared in Card Party. If someone unluckily found one, it would steal the finder's star and give it to someone else. In Mario Party 6, a Red Boo appears in Towering Treetop and Castaway Bay. Just like any other Boo, she can offer the player to steal either a star or coins.

Mario Party 8
Red Boos reappear in Mario Party 8, in King Boo's Haunted Hideaway. These Boos sold Candies to the player. They also threw the player out of the mansion whenever they reached a dead end, and fly out of the chests and steal coins or a Candy from the player if they open one. Red Boos also appear in mini-games as Boo-ting Gallery and Specter Inspector.

Super Mario Sunshine
Super Mario Sunshine introduced new mechanics to the Red Boos. Unlike other Red Boos, the Isle Delfino variety can be frozen and turned into small platforms when touched by liquid, whether it's F.L.U.D.D.'s water or Yoshi Juice. These platforms can be used to reach higher areas, primarily in Hotel Delfino. The Hotel Manager asks Mario to get rid of the Boos haunting his hotel. Although Mario cannot completely defeat Red Boos, they leave the Hotel Delfino after Mario defeats their leader, King Boo.