He is a toy that Caillou bought from a store.
Rexy does have a short book on him that sometimes appear at the end of the show.
He is voiced by Pier Kohl.
Rexy is an toy who was bought by Caillou. He is an blue dinosaur. He is also an friend of Teddy and Gilbert who talk in the Puppet Segments. In the intro, he, Teddy and Gilbert are transformed from cartoon forms into puppet forms by Caillou's kite. He appeared in the intro of season 4 and season 5 when he imagines he is a real dinosaur when Caillou was an prehistoric boy, he and Caillou discover an prehistoric Gilbert in the intro of season 4 and season 5.
He is seen in Caillou's room in all of the episodes.
In Caillou's Holiday Movie, he was found by Rosie and Caillou during the Christmas season. Rexy and Caillou are reunited thanks to Rosie.