The ruler of earthquake-devastated Kanto. He was created by Satan as a punishment for himself after he felt remorse for killing Akira. The Slum King keeps Ryo Asuka and Miki Makimura, who are now quadruple-amputees, as his pets. He has two children, Zubaban and Jannu. While he faces off against Jack multiple times throughout the series, he is finally "killed" by a newly-revived Satan. His true identity is revealed after Satan merges Zubaban's head with the Slum King to form Zenon.