Hamtaro is very popular in Japan and so are hamsters. Since the cartoon originated from there, it's considered to be an anime (an-e-meh). When Hamtaro's owner, Laura, goes to school every day, he sneaks out to visit with all his buddies like Boss, Beju, Panda, Snoozer, and the rest of the gang!
Elephant is from the Nick Jr. show, Little Bill. When Little Bill goes to the pet store, he isn't sure what kind of pet he wants. The pet store owner shows him all kinds of pets, but Little Bill decides that a hamster is the best choice for him. He takes him home and names him Elephant after his favorite animal.