Any Guesses On Breed? (Chick w/ mostly black plumage) VIDEO
Looks like a Barred Rock to me. I have had 2 barred rock chicks and both of them looked almost exactly like that. Yours is just missing the whitish yellow spot on it's head. Hope this helps!
That is not a Barred Rock. Barring requires the white dot on the head. That shows the barring to come as the bird matures, and a Barred Rock must be barred.
I'm thinking it has the posture and body shape of a game bird, although it could just be awkward juvenile stage...which case it might be a Black Sex Link or an Australorp.
But the tail carriage and wing tips that are longer than the body, with a general size comparison to the Sebright (which are tiny) indicate to me it too is a bantam size chicken.
My guess is Game Bird of some sort...possibly Black Sumatra...or simply Old English Game bantam. If Sumatra, the comb should be a pea comb (I can't see what comb type it has in the video other than it is not a rose comb).