4x16 - Dragon Ball Z: Dragon Box

Cell, a monster who possesses a Ki identical to both Goku and Freeza, appears before Piccolo. Piccolo faces off against this unknown new foe. As if to sneer at Piccolo, Cell uses his own knockout technique, Makankosappo, against him. Then, to finish off Piccolo, who is unable to hide how shaken he is, Cell assumes the Kamehame-Ha pose. Exactly who is this terrifying monster?