Black Opal is a blue-grey colored boy Siamese cat from the Japanese company Sanrio. He has grey fur, brown tips on his ears, brown paws, a brown tail, black oval eyes, and a brown oval nose. He wears a necklace with a dark blue-grey spade pendant.
He is the youngest and one of the Siamese cat siblings from the Jewelry Family who moved in next door to Charmmy Kitty. He is usually babied by his sisters and although he gets along with all four of them, he desires to be his own boy, without upsetting his sisters. He also can be a bit clumsy at times.