Who is The Cat from The Looking Glass Wars and what is their importance?

The Cat is an assassin Redd has created out of her imagination. The Cat is a cat-like creature who can disguise himself as a tiny kitten or grow to his full image as a large, cat-like killing machine. Like most cats, The Cat has nine lives. Redd does not hesitate to take three of these lives when she becomes annoyed with The Cat. Although The Cat is a dangerous and successful assassin, he fails multiple times to kill Alyss. In the end, The Cat escapes with his final life into the Heart Crystal.