Have to second that. You can head over to the Q&A board, submit a form with the question and a picture of it to have the App Team go over it and give a hard yes or no, but I highly doubt something that crossed over would be allowed.
Ruus has the right of it; draw up a concept, post it up and folks can give you some suggestions on where you can go with it to keep it approvable but still have the look you're going for. Quick sketching in my head, I'd say a centurion-esque helmet would probably work best with one of the follow elements; something like the mohawk, something like the headbutt plate or something like the back of the neck flare. Two of them, or all three, and you're at crossover rather than inspired by.