It may still be a full Pekin female the regular size and not Jumbo Pekin, My females are smaller than the drakes
Doesn't look mixed to me? then again hard to say with absolution. Does it sound like a drake? females are smaller..
I have found that the drakes I get from private breeders are a lot smaller than the ones I have bought from commercial poultry houses, and I have standard sized pekins. My private bred drake is only slightly larger than his hen, but my commercial drake is HUGE! The hens are pretty consistent in size.
He's defiantly a boy because he mates with my female muscovy and tried to get at my chickens when he escaped the duck run one time. Maybe he's just small? I love him to pieces anyway!