The Boom Rocket is found in certain chapters as a usable item, usually in an area where it would be useful. It can also be found randomly in Together Mode, where it is slightly trickier to use against player-controlled opponents. It is best to hide the Boom Rocket in a crowded area by looking for a corner or a wall to plant it; this way, no one will see it and, when it blasts off, no one will be aware that an explosion is about to happen.
These rockets first launch skyward, after some time falling back down and unleashing a massive explosion when they land. The delayed attack makes them a bit tricky to use but effective in areas where foes are likely to gather.