Randy Somkebombing in the cafeteria.
Smoke-Bomb (Bomba de Humo in Latin Spanish) is a way to teleport that the Norrisville Ninja is capable of. It is unknown whether the smoke-bomb has the power to teleport or just gives the ninja a way to sneak away.
It is revealed in Silent Punch, Deadly Punch that the Ninja Suit has a limited stock and it needs the sap of a special tree called the Skunk Pine to make it so not even one so be wasted as the ninja could be followed or traked without one.Randy can also take smoke-bombs out of the ninja suit and use them when he is not wearing the Ninja suit. Randy also uses it to temporary evade the opponent in order to think of a way or use Ninja nomicon for advice which he did in Attack of the Killer Potatoes. Randy uses it to show off in front of other students in Last Stall on the Left and wasted one of it too in the episode. Which the nomicon advise to not simply use smoke bombs as they are limited and tool of strategy but not a toy for a show. Randy soon start not waste any of the smoke bomb.
The smoke bombs apparently have quite a pugent odour, as both Randy, Howard and S.Word Smith pointed out that they smell like farts. It is worth noting that the odour stays on for a while as that was how S.Word Smith was able to figure out that Randy was the ninja, he "reeked of smoke-bombs".