I'm guessing it's some standard sized chicken, not a bantam. McMurray won't let you order just one bantam with a group of larger chickens, so they probably did not ship one for your mystery chick either.This is a mystery chick from McMurray Hatchery. It is half the size of the RIR, Wyandottes, Leghorns & Orpington. I'm guessing Old English Game Bantam. Thoughts?
I'm seeing clean legs (no feathers), no extra toes, no crest on the head, no muff/beard on the face. I cannot tell what kind of comb.
Maybe a Silver Phoenix?
https://www.mcmurrayhatchery.com/phoenix.html
They are a small breed but not an actual bantam, and they have striped chicks.
Most mystery chicks sent by McMurray are male. So without even looking at the photo, I would guess male. (After looking at the photo, I can't tell, because of how young it is.)Guesses on cockeral or pullet?