Infinite explosion glitch
The infinite explosion glitch is a glitch where Snake's mines (his down smash) will continuously explode indefinitely. There are 2 ways to recreate this glitch, one is with the help of a Smart Bomb and the other one with the aid of King Dedede's Inhale.
The glitch can occur when Snake's mines came contact with an exploding smart bomb. The mine will start to continuously explode once the smart bomb's explosion touches the mine. This results in the mine exploding constantly until the smart bomb's explosion ends.
In the other case, when King Dedede uses Inhale at a certain distance from the mine, the mine keeps on exploding until Dedede is attacked, stops using the move, or something else comes into contact with the mine. The explosion (if an opponent hits it) is like being hit by 2 or 3 mines at once. Kirby can only do this by inhaling King Dedede and copying his Inhale.
Explanation
The glitch appears to involve the mine constantly restarting its explosion sub-action each time it is hit, instead of running it only once. In most cases the object that detonates the mine will be interrupted, damaged, or erased on contact, but the constant rapid-hitting Smart Bomb and similar disjointed rapid-strike hitboxes (such as constant wind attacks) can constantly hit the mine before it deletes itself.
