The Ring of Catsumi was a golden ring with a design that resembled the head of a cat. The cat was golden and had green eyes.
It could make 9 replicas of someone, each with its own special personality. However when used for a long time it could make the replicas unstable and dangerous.
Jack Spicer was the first to own the Ring of Catsumi. After Chase realized that Jack was spying him, he sent his cat warriors to kidnapp Jack. He stole the Ring of Catsumi and gave it to Shadow. Shadow transformed into Willow and gave the Shen Gong Wu to Dojo, so that Dojo could give it to Master Fung as a present. Ping Pong found the Wu and in order to finish his chorus in time he used it.
However Ping Pong's replicas were out of control, so the monks had to do something. Omi used the Ring of Catsumi to combine Ping Pong replicas, but the real Ping Pong was kidnapped by Chase. When reptilian Ping Pong came to destroy the monks, they used the Ring of Catsumi to combine the last Ping Pongs left.