Yakumo Oomori (大守 八雲, Ōmori Yakumo) was an executive of Aogiri Tree and the founding leader of the White Suits from the 13th ward. Typically, he was called by his alias Yamori (ヤモリ, lit. "Gecko"). Due to his brutality, he also became known as 13th Ward's Jason (第13病棟のジェイソン, Dai 13 Byōtō no Jeison).