Fox Devil

At full size it resembles an arctic fox swollen to monstrous proportions. Concentric rings fill each of the many eyes scattered across its huge vulpine head, and the single forelimb it sends through contracts is just as enormous, tipped with great claws and studded with still more eyes. Its coloring shifts between adaptations: the manga gives it warm orange or pale brown fur, while the anime turns the coat white and lights its eyes with a glowing red-orange.

It feels no hesitation about devouring its own kind, cheerfully seeking Aki Hayakawa's go-ahead before gulping down the Leech Devil. Toward people it is warm enough to hand out contracts freely, yet a shallow vanity runs underneath: only those it judges handsome are allowed to summon its head. Hybrids disgust its palate, and after a single bite of Katana Man or Reze it complains and withdraws, proof that loyalty to a contractor counts for little once a fight turns sour or a meal tastes wrong.

The devil settled in Kyoto and struck bargains with Aki Hayakawa, Hirokazu Arai, and a number of other hunters, each feeding it scraps of their own flesh in return for its strength. By forming a fox-head shape with the hand and calling out Kon!, a contractor summons a piece of its body from afar to strike before it vanishes in smoke. Aki first calls on it to bite the Leech Devil in two and rescue Denji. Its limits show over time: it cannot reach Aki inside the Eternity Devil's sealed loop because its true body stays in Kyoto, and hybrids give it nothing but trouble. It gags on Katana Man, who simply carves his way back out of its head, and later spits out Reze with the same revulsion.

Having been used carelessly, the devil sours on Aki and refuses to answer his call for a time. Its head and paws still surface in other hands, swallowing Reze for the Division 2 Vice Captain before fleeing the taste, and crushing the dolls Santa Claus controls when Nakamura summons a forepaw. Sturdy and powerful despite how many contracts it spreads around, it shrugs off being summoned inside a building and levels the structure rather than taking any harm itself.