Bombchu

Ocarina of Time
Bombchu in Ocarina of Time are bombs that crawl along the ground and up walls. Link can find them in a number of places. Some for free, found in some of the treasure chests in dungeons. After finding 40 Gold Skulltula Tokens, Link can collect some from the 4th son at the House of Skulltula in Kakariko Village. Others are won from the Bombchu Bowling Game where it is also possible to win a Piece of Heart or an upgrade for your Bomb Bag.

Majora's Mask
Bombchu in Majora's Mask are self-animated, named Real Bombchus. They are found in the dry, desert area of Termina near the entrance to Ikana Canyon and are also one of the major inhabitants of the region. Whenever Link passes by they immediately carry out their kamikaze style attack by blowing up near the player. They can be repelled by holding R to block them with the Hero's Shield or the Mirror Shield. Bombchus are also a type of weapon, bought from the Bomb Shop, that run up walls just like in OoT. Bombchus are also what Rats holding a Bomb are called in Wind Waker. In Wind Waker Bombchu is the name given to a rat that is carrying a bomb. They are most prevalent as the main inhabitant of the Forsaken Fortress.

Phantom Hourglass
In Phantom Hourglass, Bombchus are found in the Goron Temple. They are the only items which can go through small holes in walls. When used, the map goes to the bottom screen and enlarges, and the player must draw the path that they want the Bombchu to take.