Cathy Katherine, known simply as Cathy (キャッシー, Kyasshī) in the manga and Japanese version and nicknamed Cat (Cat-chan in the manga and Japanese version), is a supporting character appearing in Yu-Gi-Oh! She has an obsession with cats to the extent that she behaves like them and can control and communicate with them.
Cathy, like her nickname implies, has the appearance of a cat.
Later when the building was beginning to explode, she was reluctant to leave as she along with Tori didn't want to leave Yuma and was seen mourning his death after the building had collapsed but was overjoyed to see he was alive when he emerged from the rubble.
Cathy attended the World Duel Carnival opening ceremonies with the rest of her friends and was surprised at Yuma not receiving a Heart Piece.
She has black and white over-knee high socks and black shoes.