television series debuts 2000 American television series endings 1990s Canadian animated television series 2000s Canadian animated television series 1999 Canadian television series debuts 2000 Canadian television series endings 1990s preschool education television series 2000s preschool education television series American children's animated comedy television series American children's animated fantasy television series American preschool education television series Animated preschool education television series Canadian children's animated comedy television series Canadian children's animated fantasy television series Canadian preschool education television series Fictional duos Fictional hippopotamuses YTV (Canadian TV channel) original programming HBO original programming English-language television shows American television shows based on children's books Canadian television shows based on children's books Television series by Nelvana Australian Broadcasting Corporation original programming Animated television series about mammals Television shows set in the United States