Sesame Street, a popular cartoon muppet show, is going introduce an autistic character.
Julia, an autistic girl, has been displayed in cartoons and books, but has not appeared on the children's show. The developer seems to utilize Julia's unique character to enlighten youth audience to let them know autistic disorder precisely.
The Guardian: Sesame Street introduces muppet with autism to teach children about disorder
There are several works featuring autism. "Elephant Man" is one of the most popular films whose hero has autism. Mark Zuckerberg in "Social Network" is also described as if he has Asperger's syndrome, though I do not know the real Zuckerberg is autistic.
However, it is relatively rare to describe a person belonging to the minority in films or comics for children. Children can bully those who share the characteristics of the person in fiction. Especially Japanese teachers and parents are likely to think so.
Linus in Snoopy has some characters of autistic syndrome. He always keeps security blanket and believes in Great Pumpkin while he is fond of philosophic thinking. This unbalance of thought and behavior is typical of autistic people. But he is not explicitly described as autism.
Nobita and Gian in Doraemon, a popular Japanese cartoon, was described as ADHD by Eriko Shiba, a child psychiatrist. Actually, however, they seem not to have ADHD, for my sense. Maybe Shiba utilized them to make a simplified explanation of ADHD.
By the way, men are much more likely to have autistic disorder than women. In this sense, Julia is not typical as an autistic child. I guess autistic girls are easier to describe in fiction than boys.