The Aku Aku and Uka Uka masks are weapons used in Crash Team Racing and Crash Nitro Kart. They make the player temporarily invincible. As the player's kart goes, it travels faster and faster in the duration of the mask's use and wumpa fruit won't be lost if the player falls into an abyss. While using them, the player can crash into opponents and make them spin out. While using it, the race track's music is interrupted by different music. The music that plays depends on which mask the player is using. Juiced up masks last a bit longer and the wielder moves even faster.
In Crash Team Racing, Aku Aku is used for characters that are considered to be good, and Uka Uka is used for characters that are considered to be evil. In Crash Nitro Kart, Aku Aku is used for members of Team Bandicoot, and Uka Uka is used for members of Team Cortex. The Velo Mask is used for members of Team Oxide and Team Trance. It is also used for the bosses in the same game.