The Black Devil" Yahya "Beastar

Yahya at first sight seems to be a pretty friendly and reliable animal due to being the Beastar. However, he is also quite manipulative. He has a strong desire to bring about justice and make a change in society and will often manipulate other animals as a means to an end. This has led him to have many enemies, as shown in the death threats graffitied on the walls surrounding the Black Market.

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He uses the bodies of carnivores he punished to fertilize his carrot farm and because of this, he is hated and known as the "Black Devil" by residents of the Black Market. He is capable of cruelty to not only carnivores but herbivores as well, as seen in Chapter 138 after threatening the leader of the 500 Cornered Rats during an interrogation.

(Source: Beastars Wiki)