is a 4 year old who is one of Caillou's friends. He has the eyes of Rosie. He is robot(more on that later.... Okay. He has a twin brother named Jeffery. Jason and Jeffery first appeared in Season 2 in the episode New House, New Neighbors. Back then he and Jeffery both wore identical clothes (red shirts with a white stripe and pants) but, in Season 4 Jason began to wear a white shirt with a red stripe and they are now able to be told apart. In the episode Caillou the chef Caillou gets Furious that the boys put Pinaaplle on their Pizza. Canada isn't free like USA! OKAY! Jason has a toy spider named Boris. Towards the end of Season 2 he and Jeffery began coming to Caillou's preschool class. In Seasons 2 and 3, he and Jeffery appear to be mischievous and sometimes a little mean to Caillou but, in Season 4, they are nicer to Caillou and more of kind people Caillou is mean, but it is okay he is sick. EXCUSES. He is voiced by Adam Lawn Mover. His brother and him are from a Canadian Lab called "M.B.L.L" or otherwise known as "Maple Bacon Leaf Labs" where artificial intelligence is born. Jeffrey and James are clones made out of the single strand of hair from these twins found in the remains and destruction from the Great Canadian-Antarctica War. They were shot straight between the eyes. Why? The world will never know. But what is their Robot mission? Keep watching the show to FIND OuT!


Note: Although Jason and Jeffery are twins they don't appear in all the same episodes Jason doesn't appear in the episode that Jeffery appears in Garage sale and Jeffery doesn't appear in A surprise for Ms.Martin

Caillou's Preschool class
Caillou Clementine Emma Jason Jeffery Leo Xavier

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.