Allen is a 5 year old boy who lives in the same neighborhood area as Caillou. He is a playful and imaginative child, but has trouble learning how to do some things such as climbing and swinging because he has Autusim down syndrome, however this was never explicitly stated in the episode. He went to Caillou's Playschool to try it in Caillou and the Dragon and enjoyed his time there, but has not yet been seen in any other appearances to date. It is believed he was not accepted due to condition. Bummer Man. Or he moved. Or he died. Also maybe he was born in M.B.L.L and is a malfunctiong clone. They have been hacked. The Canadian-Clone War is soon to come?