Jack (ジャック, Jakku) is an underground beyblader and a minor antagonist.


He was chosen to wield the invisible wind Bit-Beast, Sickle Weasel. He challenges Kai and severely hurts him as Kai is unable to see his Bit-Beast. Once Kai is able to see his Bit-Beast he summons Dranzer and destroys Sickle Weasel at the cost of damaging his own beyblade even further.