Many characters from the kids shows/animations I know have a-sexual or ambivalent traits. Particularly the Japanese animes, which can often strikingly differ from the 'gender-amplified' American cartoons. You can tell it from for instance the fact that many male characters (children or adults) in animes are voiced by female actresses in the original Japanese versions, while they are voiced by 'tough' male actors in the American versions. Dragon Ball Z is a good example: Goku (an adult male fighter) is voiced by a female; Gohan (Goku's son) is also voiced by a female; Kuririn (Goku's friend and male fighter) is also voiced by a female; Freeza (one of the strongest villains) is voiced by a male but has no physical characteristics of either male or female while relatively anthropomorphic. In another very famous and influencial Japanese manga called JoJo's Bizarre Adventure, many supposedly male characters have somewhat female looks (while the author is a married male heterosexual):
http://www.onemanga.com/Jojo's_Bizarre_Adventure/470/01/