(PBS) In this animated TV series, Caillou is a 4-year-old boy who delights in the small wonders of the world around him, embellishing everything he sees with his rich imagination. Surrounded by his parents, his little sister, Rosie, his grandparents and friends his age, Caillou discovers the world and just can't wait to grow up! Everything around him is an excuse to embark on exciting adventures, learn new things and have fun. Whether he's at school, at home or in a park, Caillou finds opportunities for learning and growing everywhere.