I was referred here by the Jersey Giant thread. So here's my original post from another thread:
I'm trying to identify a mystery chick we "rescued" out of an assorted pullet bin. (She didn't need rescuing, but was oh-so-cute, and the boyfriend didn't even try to talk me out of it!)
She's all black on her feet, comb, beak, feathers, even her cute little eyes seem black. I've heard about black combs maturing into red, but for now hers is still black.
These pictures, she's about 2 weeks old. She does have a little bit of greyish feathers on her underside, if you can tell.
This pictures she is almost 3.5 weeks old.
And here she is today around 5 weeks old.
So she's black, with some coppery/brown feathers coming in as well. Could she be a PR?
I did get her from our feed store who gets their chicks from MM (Murray McMurray, right?). So it's got me a little concerned since you said some of their strains are aggressive! So far, little Georgette is quite sweet and docile. She doesn't particularly like to be picked up, but she's not as terrified of us as some of our BRs and EEs have been. Thanks in advance for your help! 
Edited to add image tags. *DOH!*