Hackmon is Rei Katsura's Buddy Appmon.
He is voiced by Daisuke Sakaguchi also voiced Jacuzzi Splot.
He look like Hackmon but different color.
He have black armored skin, red claws, red eyes and horns. He wears a purple cape with a monster face hood.
Digimon Universe: Appli Monsters
Haru and others are lured into an ambush by Hackmon and his Appli Driver Rei Katsura, who challenge them for a fight.
Haru, Eri, Torajirou and Rei are attacked by the Ultimate 4, a team of powerful Appmon under Leviathan's that easily destroy both their buddies and AppliDrives. Just as they are about to be killed as well, Yujin and Shutmon appear and face the enemies by themselves to help them escape.
Rei and the others reunite with their Appmons, who do not remember them at all, and are sent to a journey to restore their buddies' memories. In the occasion, they not only reconnect with Hackmon and the others, but obtain each one their own AppliDrive DUO.