Just based on the comb, feather points, and the curved feathering at the tail, I'll vote roo. If you have a photo of it (from the side perhaps) standing on its own in a natural position, the bird's shape could tell. Not knowing the age, I cannot speak to size really, but could it be a bantam?
I do not know the age, I got this bird and several others 2 weeks ago.
They are Black Japanese Bantam.
They are not used to me yet, so I can't take a picture of him/her normal, lol.
I looked through my other pictures and I could not spot this bird in them, at least not standing or a good picture.