When does Caillou: Adventures with Grandma and Grandpa return?

Caillou (transl.?pebble or stone; /k??j?, -ju?/ ? kah-yuu, -?yoo; French: [kaju], stylized in lowercase) is based on the books by Hélène Desputeaux. The first episode aired on Teletoon on September 15, 1997, until the fourth season. The series received initial positive reviews from critics and audiences. In the years following its release, the series saw a more negative reception and sparked backlash.