Well, is he like this all the time or only when he's sleeping? The one foot things is a good sign, since that means that he's just resting the other foot, and is comfortable enough to do it without fearing attack.
A bird are just puffy when they sleep? If since it's winter here, my birds are puffy when they sleep.
If he's like this most of the time, though, I would see a vet since that's a sign of sickness.