All about Kero...

Kero is the guardian beast of the Clow Book. (the book holds the Clow Cards) When sakura opened the book, Kero emerged and made her a Cardcaptor. He helps her find and capture the cards. Kero also loves to eat and play video games. He's a real ham, and he's very cute in his small form. When he turns into his true form, he grows very large, and he looks sort of like a lion! (when he does this, he prefers to go by his full name "Cerberos." Kero is a nickname)