The butler of the Beast Friends. He is always being tormented by the beasts. Currently, he works as an intern at a small company. He always wears a green t-shirt (a green suit at work) and has a single strand of hair. His hair is yellow. He never uses polite speech with the beasts and swears a lot. Although he acts like he hates the troublemakers, he would risk his life to protect any one of them if they were in danger. He has a girlfriend (Daseul). He is a soup-and-rice fanatic.

A male grey kitten (not neutered). He beats up Yoo Sumin frequently. Originally Daseul's cat, but he ran away and is now living at Yoo Sumin's house. He has no father. He swears a lot, especially using the phrase 'You son of a b*tch!!'. He ends every sentence with 'ttang' or 'kkang'. Surprisingly, he uses polite speech. He calls Yoo Sumin 'Butler' (and Daseul 'Female Butler'). It seems his dream is to live with his father again. Ttangttangi's Mother: Christine Elizabeth Aguilera von Carbonara I Ttangttangi's Younger Sister: King God Emperor Chungmugong Hyper Gopchang II Ttangttangi's Original Name: Gaius Julius Caesar de Clementine Ssalboribori Jamjam II

A male Shiba Inu (not neutered). He communicates by writing on a sign he received as a keepsake from his mother when he was young. He swears a lot. Originally the dog of Yoo Sumin's best friend, Jung Jichan, but Jichan left him with Sumin and never picked him up, so he still lives at Sumin's house. He never speaks. He exaggerates his pain. He beats up Yoo Sumin frequently and uses informal speech. It seems his dream is to live happily with his mother.

A male lab rat (not neutered). He is the only normal and kind one among the Beast Friends. He was a lab rat who escaped after being experimented on and came to live at Yoo Sumin's house. He has a yellow tail. He is surprisingly talented in things like grooming and Bitcoin. He draws well. Occasionally, his personality changes to be like the other Beast Friends. When he gets extremely angry, his body grows huge and becomes incredibly muscular. He ends his sentences with sounds like 'syum' or 'dyang'. It seems his dream is to become a famous artist.

A male pigeon (eunuch). He was neutered as soon as he met Yoo Sumin. Because he hit his head on a window, he has a short memory and asks 'Who are you~?' after just a little while. He ends his sentences with 'yong', is surprisingly good at delivering harsh truths, and is good at fighting. He cries whenever he is teased for being a eunuch. If he gets hit hard on the head, he becomes incredibly smart, but if he gets hit again while smart, he returns to his stupid state. Ironically, he behaves the least like a pigeon. It seems his dream is to start a family.