Ddang-ddang-i: A male cat with gray fur. He causes trouble every day and doesn't hesitate to wreak havoc on anyone. Kim Hyun-sik: Despite the human name, he is surprisingly a male Shiba Inu. He doesn't speak and instead writes what he wants to say on signs. He also causes various incidents, though not as much as Ddang-ddang-i. Saedaegal: A male pigeon who is incredibly stupid, with a memory so poor he forgets what he was just about to do. He is the only one who has been neutered. He often says, "Who are youuu?" Syum-dyang-i: A male white lab mouse. When he gets angry, his body grows massive. He is the only one who treats Yoo Soo-min like a human being. He is kind and the only one who doesn't use foul language. Lona: Having been experimented on by humans in the past, she is friendly toward other small animals but harbors a deep hatred for humans.