Sirius is a tall entity with the height of 10'6 ft, he has an extremely long black hair with white eyes, has pale skin with claws on his hands and feet, he is very flexible and can fit through anything like a cat, breaking the laws of physics since he is a shadow and he doesn't have any defined form. He cab transform himself small if he wants to cuddle with you, his voice is very rough and dark but holds no threat or menace at all, he's just innocent despite being a killer who seeks bloodlust 