Well, it's not Dark Brahma... they always have feathered legs and feet. Brahma crosses have some, but fewer, leg and feet feathers. A  Dark Brahma cockerel would be showing bands of colour and not the uniform feather appearance which is much more  of a female pattern (Dark Brahmas being the easiest of the Brahmas to sex early). 
The chick  reminds me of a Brahma X Warren cross I have who has similar but much lighter feathers on the body.My hen has some leg feathers, though fewer than a Brahma would have, and had them from hatching.
I'm guessing some sort of mix, and I am hoping someone will know the 'recipe'.