I think this aired in Nickelodeon. All I remember was that it was a cartoon that seemed to take place in a dystopian future. There was a floating green face going around looking for a boy who was hiding in some ruins. It seemed like the green face was the antagonist, and it kept going, “Toby? Toooooooby?” It was strange.
There’s a chance the movie is “Fantastic Planet”.
http://www.imdb.com/title/tt0070544/