Topsy is a grey kitten. He is one of Tom's alley cat friends/foes, although in one cartoon he befriends Jerry. He first Topsy appeared in Baby Puss; his final appearance in the original theatrical shorts was in Scat Cats. He also appears in Tom and Jerry Tales with a more yellowish color than before. In Professor Tom, Topsy is explicitly a house cat; more often (as in Saturday Evening Puss and elsewhere), he is depicted as an alley cat or a cat of unknown origin.
He has grey fur.