Dog

Known in Japanese as Inu, Dog is a close range Mutant Quirk that debuts in chapter 56 and reaches the anime in episode 31. Three characters are on record with a version of it: Gigantomachia, Kenji Tsuragamae, and Ryo Inui.

At its core the Quirk trades a human profile for a canine one and hands over an animal's sensory range. The physical results differ noticeably from one holder to the next.

The shared foundation is perception. Anyone carrying Dog hears and smells at ranges well beyond ordinary human capability, and that heightened pair of senses is the one trait every version reliably delivers.

Past that baseline the Quirk expresses itself as physical caninization, grafting dog anatomy onto a human frame. How far the mutation goes changes by person, running from a partial coat of fur and claws all the way to a complete animal head. Whether it also lifts strength or speed has never been spelled out, though Ryo Inui's build makes some measure of physical uplift a fair inference.

Ryo Inui shows the most thoroughly documented version. His sense of smell is sharp enough that he can stand at the edge of a forest and report how many people are concealed inside it. The animal traits are all present on him too: a long dark snout, a coat of fur, clawed paws. Nothing further about his particular version has been established.

Gigantomachia puts the same heightened hearing and smell to a narrower purpose. He can pick his master out and track him down from miles away, which makes the Quirk function for him less as a weapon than as a homing instinct.

Kenji Tsuragamae's mutation sits mostly above the neck, setting a dog's head atop a human body. It leaks into his behavior too, surfacing as occasional canine tics such as woofing while he talks.