I think the green guy in front is going to be some made up species of frilled lizard that gains the ability to use a camouflage move. The other and harder to see character will probably be some sort of bird or bat. Personally I'd prefer to see a bat, but some sort of bird would be nice too.
As for the way the two stick together a yellow backpack maybe?
And our scaly friend can wear blue shorts too!
Either that or the other character can hang on for dear life to the lizard's frills like some sort of horse or something!