Probably not if they came from Tractor Supply. All their chicks come from major hatcheries, and last time I checked there were no major hatcheries selling Seramas (too tiny and fragile at hatch to ship safely.)
No, not really.
You are probably thinking of Cornish Cross, which are big white meat birds.
There is a breed of chicken called Cornish that comes in both standard sized and bantam. The "Cornish Cross" meat chickens are called that because Cornish was one of the breeds used in the crosses when they were being developed.
The actual Cornish chickens (not crossed) can live a normal chicken life and are about as healthy as any other chicken.
Cornish bantams have a rounder body than other bantams, and they do have more meat than most other chickens of the same size. If you want to eat them, of course you can. But they also make nice little pets, and can lay as many eggs as most other bantam breeds.
I was thinking it might be an Easter Egger bantam.
It does seem to have a pea comb, which is right for Cornish, Brahma, and some Easter Eggers. But the clean feet are wrong for Brahma, and the feather color is wrong for any variety of Cornish or Brahma that I can think of, which is why I'm guessing Easter Egger bantam.
