Bat Devil

In his original form the Bat Devil is a hulking, man-shaped bat with a heavily muscled frame. Broad membranes of skin stretch between his arms and torso, doubling as wings, and his face is a nightmare of bulging round eyes and rows of pointed fangs. He first appears with his right arm gone, a wound that only mends after he gorges on Denji's blood, and during the same battle he loses that limb a second time. A caged Meowy dangles from a chain at his neck for part of this period. His hide is a deep purple in the manga, swapped for a plain dark grey in the anime.

His revived body looks altogether more bestial. The muscle is gone, replaced by a shaggier, softer bulk, and his eyes stay permanently bugged out above a fleshy snout and a jaw that never closes over its uneven teeth. Fur covers his arms only to the elbow, where they give way to almost human hands trailing wing-like flaps, and his feet end in talons resembling an eagle's.

His first life is defined by loathing for humankind, a grudge rooted in the people who maimed him and drove him underground. He fancies himself a creature of discerning palate, sorting humanity into dishes to be savored and dismissing both Denji and Power as foul-tasting. Children and able-bodied adults rank among his preferred meals. For all his viciousness, he is not incapable of tenderness, having once been the lover of the Leech Devil, a partner left to grieve when he was slain.

The Devil that crawls back to Earth later bears almost none of that character. Stripped of his wits and apparently unable to speak, the reincarnation behaves as a purely savage thing, driven by instinct alone.

Before the events of the story the Bat Devil had taken the Leech Devil as his lover. A human nearly killed him once, and he fled the encounter short an arm, going to ground in the countryside. There he cornered Power and seized her cat Meowy, locking the animal in a cage to force her cooperation; he ordered her to deliver a living person whose blood could restore his missing limb.

Power lures Denji to him by claiming a Devil has stolen Meowy. After knocking Denji out, she hauls him into the lair, and the Bat Devil crushes the boy to drink the blood streaming from his wounds, regrowing his arm even as he gripes about the taste. He then swallows Meowy's cage whole and gulps down Power for good measure before launching into the sky to hunt the city for more prey. Denji, however, has clung to his leg and bitten him; the squeeze meant to kill the boy instead lets him yank his cord, becoming Chainsaw Man and slicing into the Devil as the pair plummet. Denji shears off the freshly regrown arm, and their brawl tears through a city building and out into the streets. The Bat Devil hurls a car, betting his foe will rush to save the driver, but Denji simply flings it back into his face. In desperation the Devil reshapes his maw into a gun barrel and fires a blast of compressed air that buries Denji in rubble, yet the boy climbs out unharmed. Cornered and afraid, the Bat Devil throws a final punch; Denji drives a chainsaw through the arm, runs it up to the head, and carves the creature apart.

Death only sends him to Hell, where he dies again and wakes once more on Earth. Now a mindless brute, he tears through the city devouring its residents until the scent of Yuko and Asa Mitaka reaches him and sends him after them. He swallows the two girls whole, but in that instant Denji slams the Cockroach Devil into the building with such force that the Bat Devil is killed on the spot, spilling the pair back out of his mouth.