a Teen Titans question

Uhm, I feel kind of dorky asking this, but how does Gar's costume work? If it was green I'd just assume that it is not clothes at all but part of him changing forms, but as it is it looks like he wears clothes when he's in human form, nothing when he's an animal, and the clothes just conveniently reappear. Of course I'm aware that he has to have a costume for extra-textual reasons, just like Hulk has to keep his silly ripped shorts, because they don't let superheroes frolic around naked in mainstream titles, but is there any explanation within the fictional reality?