Janemba expels multiple orangish-yellow energy spheres from the cannon-like holes on his body and guides them towards his opponent, creating a huge explosion. Janemba uses this attack during his battle with Super Saiyan 2 Goku in the movie Dragon Ball Z: Fusion Reborn, though the Saiyan manages to dodge the blasts. Angry, the giant demon spins on his head and fires more blasts until he falls on his stomach, causing the blasts to explode on him.
Appearances in games
Rapid Cannon was named in the Budokai Tenkaichi video game series, where it is one of Janemba's Blast 2 attacks in his first form. Janemba also uses the attack in Dragon Ball Z: Ultimate Tenkaichi, during his boss fight.