With an animal in this condition I think a tub might be your best bet for a while. I don't have a clue what you're talking about with a pillow case. Get an old cool whip container and put a warm wet cloth at the bottom and put him in then close it up. He'll have plenty of air for a good 20-30 minute bath. 20 qt steralite tub will probably be big enough. However, it's hard to tell without seeing the animal in person. Go with something so he has room to move with heat gradient. He looks around a year or so from the photo, maybe more. It's a biak type from the photo and they can take up to two years to complete their color change. I'd probably give him a better perch, I'm glad this guy is no longer able to have it. It looks very neglected to me. That's my personal opinion, take it as you wish.