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 are the second most quick type of Boos in the mode with the Black Boo being the quickest. After Mario defeats Red Boo a good amount of times, he will then move on racing Black Boo.

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 serve 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 appear in Card Party. If someone unluckily finds one, it steals the finder's star and gives it to someone else. In Mario Party 6, a Red Boo appears in Towering Treetop and Castaway Bay. Just like any other Boo, it can offer 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 sell Candies to the player. They also throw the player out of the mansion whenever s/he reaches a dead end, and they fly out of the chests and steal coins or a Candy from the player if s/he opens one. Red Boos also appear in mini-games as Boo-ting Gallery and Specter Inspector.

Super Mario Sunshine
Super Mario Sunshine introduces 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.