I agree with what others have said about posting again to confirm the sex when it is older, but due to the size of the comb I am going to guess cockerel, especially when it is compared to the other chick. The larger comb size is a big indicator of a male chicken, as all of our cocks have had big combs when they were young, but again I could be wrong. I am hoping for you that it is just a pullet with a large comb! We had one hen that was like this and everyone thought she was a rooster. You never know! Good luck to you and these little cuties!