Time Bomb (item)
From the Super Mario Wiki
The Time Bomb is an item in Mario Kart Arcade GP, Mario Kart Arcade GP 2, and Mario Kart Arcade GP DX. They resemble a bulky metallic dynamite with a time countdown display and yellow feet similar to those of Bob-ombs.
The Time Bomb is a lock-on item. Upon hitting a racer, the Time Bomb hovers above them and initiates a countdown starting at fifteen seconds. The racer with the Time Bomb may pass it to another racer by bumping into them. When the countdown reaches zero, the Time Bomb explodes on the racer it is currently hovering above, bringing the racer to a complete stop and blasting them high into the air.
Two variants of the Time Bomb exist - the S variant and the L variant. The Time Bomb S is smaller and produces a blast that can only hit one racer, whereas the Time Bomb L consists of three explosive packs rather than one and produces a much larger blast. Both variants count down from fifteen seconds.