Varanus

Bone covers his face rather than cloth: the skull of some animal, strapped on as a mask. He stands noticeably shorter than the criminals crowding around him. A heavy hump rides between his shoulders, and the neck emerging from it runs long, so the whole silhouette reads as something reptilian instead of human. Red lines mark both arms, his eyes are black, and below the waist he wears little beyond green trousers held by a black belt.

His alias follows the theme: Varanus is the genus that covers monitor lizards.

Tomura Shigaraki's recruitment drive scraped together dozens of low-tier criminals, and Varanus signed on for what became the raid against U.A.'s Unforeseen Simulation Joint, which made him a footnote antagonist of that arc. He came in with the horde and joined the pile-on aimed at Shota Aizawa.

It ended quickly. Martial Hair fell first, and Varanus went down right behind him, wrapped up by the capture weapon and the close-range fighting style the Pro Hero builds around it. Police took him in with every other recruit once the operation collapsed, and prison has held him since.

His Quirk carries no name on record and no described effect. Erasure switched the power off and a length of binding cloth settled the fight before he could demonstrate anything, so whatever the League saw worth recruiting was never written down.