Red Boo
Red Boos (also known as Pink Boos) are a light red or pink colored sub-species of Boos, making their first appearance in Mario Party 4. Red Boos are treated as generic Boos and they are no different from any normal Boos, with the exception of the reddish color. Pink Boos were possibly introduced to take over the roles of normal Boos, since Boo was a host and later a playable character in the Mario Party series. Alongside Pink Boos, there is a crowned variety of Pink Boos. In Mario Party 4, Pink Boos are mainly featured on the board Boo's Haunted Bash. On that board, Pink 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.
Super Mario Sunshine introduced new mechanics to the Pink Boos. Unlike other Pink Boos, the Super Mario Sunshine variety can be frozen and turned into small platforms (Platboos) when touched by liquid, whether it's FLUDD'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 Pink Boos, they leave the Hotel Delfino after Mario defeats their leader, King Boo. Pinks Boos are not the only type of Boo found in Hotel Delfino. There are also generic Boos and Sleepy Boos.