Cotton is a white tom with very soft fur and ice blue eyes. He has gray spots on his pelt
Cotton is a loner who used to be a kittypet until he escaped from his Twolegs. He lives in Cottonrose Hollow with his sister, Rose. A strange she-cat named Foxy comes to join them. She seems to have a crush on him, but he doesn't notice. It is revealed that they met their distant cousin, Rockclaw, at the sun-drown place. He also says he has feelings for Foxy, but he doesn't know that she likes him too.
He is very upset when Foxy and Ash become mates, but he understands, and is comforted by his sister. He plays with Feather's kits after they are born, and they follow him into the forest. He remembers his kithood, and they all say their first words in the clearing.
He was in a state of depression until Feather's and his sister's kits were born, but he is happy again. He meets his old friends at the hollow where Blazepelt died, and it is revealed they were born in the hollow.