[lancelot9]

The way it works is yes, once a head or anything else for that matter is created it now belongs to graal, but just because it's part of graal doesn't mean some body can edit it... The art is owned still by the creater, they can do what they wish with it, such as take it from a server, put it on another, what ever. Editing work without the creaters permissions wrong and most of the time they most likely will get mad.
Asking always helps, that way they know you dont want credit for it and that you would just like to make it more suitable for your needs.