A Thunder Cloud is an item from the Mario Kart series. It first appears in Mario Kart Arcade GP and later appears in Mario Kart Arcade GP 2 and Mario Kart Wii.
When it is picked up, a cloud will appear above the player. After a short amount of time, lightning will strike down from the cloud. This can either do one of two things; it can zap the player sporadically with charges. However, if the player does it for too long, it will zap the player too hard and the player will shrink in the process, reducing the player to that of a Lightning-sufferer. However, if the player hits someone else, they will obtain the risk.
It will disappear if the player goes through a cannon (for example, the ones in DK Mountain, DK Summit, Rainbow Road, or Maple Treeway).