Kuro

Kuro is a Servamp ( a vampire + servant). He was named Kuro, by his Eve, Mahiru Shirota, is the Servamp of Sloth. He is the oldest of the eight Servamps. When he is exposed to sunlight, he transforms into a black cat.

Being the Servamp of Sloth, Kuro spends his time sleeping, lazing around or playing video games. He feels no shame in running away to avoid any trouble and refuses to make decisions, since he doesn't want anything to be his fault, and doesn't want to disappoint anyone. Kuro is a 'shut in' pacifist vampire, and rarely drinks Mahiru's blood, most of the time he refuses and drinks only when he is about to fight. He prefers staying at home rather than going out and seems to dislike the changes of temperature, according to him vampires are delicate to this. Despite his lazy and at times comical nature (comical due to his laziness and arguments with Mahiru), he is shown to have a dark side.

Mahiru's straightforwardness and sincerity start to influence Kuro, though he always hides it by feigning disinterest and acting lazy. After Mahiru confronts him in his mind regarding his past actions and assured him he is not alone, Kuro decides to stop running away and face his past, since then he has become more willing to fight and determined to stop Tsubaki.

(SERVAMP Wiki)