Kero-chan, also known as Cerberus, is from the anime series, Cardcaptor Sakura Clear Card. He is one of the two Guardians of the Cloe Cardscreated by Clow Reed. Before his death, Clow appointed Kero as the one to select the potential candidate to be the next master of the cards, Cerberus himself, and his fellow guardian, Yue. After Sakura inadvertently releases the cards, Cerberus chooses her to be the candidate and teaches her the basics of capturing the cards.