Each country has its own tradition of wall paintings. It depends on popular fairy tales and cartoons in particular place. For example, in US and Canada you most children rooms are full of Disney characters. In Muslim countries you find mostly floral and animal patterns. In Israel strangely enough you see mostly Disney characters together with some popular anime motifs. Though sometimes people ask to paint some creative things for their kids as well.
Here is a couple of examples of wall paintings for kids rooms in Israel: