It's called Freaks of the Heartland, and it's a six-part story published in 2004 by Dark Horse Comics (Portland represent!) about a boy in a small town who must protect his younger brother from people who view him as a monster. There's a good chance the townsfolk are right about the monster thing, however, and it apparently applies to some other local children, too. It's not what I first thought of when I saw the title Freaks of the Heartland (this was), but it sounds pretty cool.
According to The Hollywood Reporter, Overture Films has hired Green to direct, with a screenplay adaptation by Peter Sattler and Geoff Davey, both of whom, like Green, are alumni of the North Carolina School of the Arts. The comic was written by Steve Niles (who also wrote 30 Days of Night), and he will be executive producer. Dark Horse founder Mike Richardson and Green will produce.
But hey! What about the fantasy comedy, Your Highness, that Green was supposed to make with his buddy Danny McBride? Is that still happening? That's a good question, and the answer is I dunno. I can't find any updates on that project since the original announcement in May. If Mr. Green is reading this and would like to contact me to clear things up, and also to listen to me gush about how brilliant I think he is, he is welcome to do so.