Well, I'm not sure what it is.
The overall color tone indicates a buff bird to come, but I do see some darkening on the wings with potential trim or patterning coming in, like columbian (black trim at hackles and wing tips and tail)... but that may fall away with adult feathers as it is in the messy juvenile stage...which may mean a Buff Orpington.....but if I assume that is trimming to come....
It appears to have a single comb, so my initial thought of Buff Brahma would not be possible....unless that develops into a pea comb (which it could as pea and single look very similar early in chickhood).
I don't think I see any, but does it have feet/leg feathers? If it does, then it may be a Buff Brahma....my first guess.
If clean legged....then....well....hmmmm....maybe a Buff Columbian Rock (if yellow legs) or a Buff Columbian Orpington (if white legs)...or simply a hatchery mix colored or even mixed breed oops.
Is it tiny, as in bantam size? Then we can go into all sorts of bantam and game types.
TSC is notorious for mystery birds in mixed bins.
My thoughts...rambling as they are.
LofMc