Well then explain how the rest of that hatch was fine.I had a Toulouse Goose and a peafowl with this same deformity. I didn't have the heart.to despatch the goose. It was picked on and isolated by the flock and eventually died after a very lonely and unpleasant little life. I took care of the peafowl as soon as I found it had the same defect.
It's caused by too high a temperature in the incubator. Feel free to Google it.