Welcome to the Official Caillou Web Series channel on YouTube! Meet Caillou, the lovable 4 year old with a big imagination in a new, modern look! Caillou experiences all the wonders of being a child that audiences around the world can relate to: Learning at school, playing with friends, going on adventures or spending time with family. Preschoolers will feel right at home with trusted pal Caillou, his sister Rosie and all their family and friends as they experience the everyday adventures of childhood.