Time Bomb (item)
From the Super Mario Wiki
The Time Bomb is an item that is found in Mario Kart Arcade GP, Mario Kart Arcade GP 2, and Mario Kart Arcade GP DX. If the player obtains it, the player can throw it to another player if targeted; otherwise, the player will use it him or herself. If used, the Time Bomb starts at 15 as it ticks down. The player with the used Time Bomb may pass it to other players by hitting one of them. If the Time Bomb reaches 0, the bomb explodes as the player is stunned at the moment, leaving other players to pass by.