Toxic Waste Human Yukan (폐기물 인간 유칸, Pyegimul Ingan Yukan) is a D-rank Regular, one of Ten Bosses and a subordinate of Kaiser at the Name Hunt Station. He was killed by the Shadow Fox, a Shinheuh spirit of Lo Po Bia Alphine.
Appearance and Personality
Yukan is a very tall and huge giant that half of his body has been modified to generate toxic waste. One palm of his hand can fully grip the body of an adult. He has many pipe hose behind his back, starting from his neck. He wears red long sleeve clothes and black grey huge long skirt. He has grey skin, but on his hand, there's a red skin which appear to be like burn mark or spotting. He wears a grey metal mask with large round horns that covered half of his upper face.
He is an authoritarian who rules using brute strength, controlling and making the weak as his army of slaves. He tend to underestimate and look down on other people who looks weak. He is proud of himself, arrogant and haughty.
Due to Jyu Viole Grace's attempt to uproot the Name Hunt Station, Kaiser issued to the remaining Ten Bosses to "absolutely not fall for the enemy's provocation, and to keep themselves completely hidden until the festival is finished as Kaiser would deal personally against Jyu Viole Grace". Upon hearing Kaiser orders, Yukan complained about Kaiser's orders to remain hidden.
Powers and Abilities
While Yukan's abilities are mostly unknown, it can be inferred he is relatively powerful for a D-rank Regular, being one of the stronger Regulars among the Ten Bosses. Yukan claimed to be the strongest of the Ten Bosses before the arrival of Arie Inieta, but started to hide afterwards.
Yukan's primary ability is that of a Waste Man. This ability allows him to eat the station's waste and convert it into an acid that he can shoot out of the metallic hoses attached to his back. This acid is said to be strong enough to destroy most defences and completely melt Yukan's victims. 
According to SIU the Waste Human doesn't spit just waste but spits it through Shinsoo. As the entire tower is filled with Shinsoo so it is everywhere but the author states there is a difference between natural Shinsoo and man-controlled Shinsoo, further explaining there are many cases where one uses their organs to change the nature of their Shinsoo for tactical use. Despite being lost against the Slayer Candidate SIU admits Yukan is strong among the D-class.