I'd put my money on his being a cornish x then. Cornish x (cross) are raised as meat birds and have been bred to grow super fast. He probably is twice as big as the others you got at the same time?
Their bodies grow faster than their feathers and so they look bare. They do tend to be hotter natured. They will need less heat sooner than other birds the same age. And they feel warm to the touch because the lack the feathering to insulate them in the same way as the other birds.
If you don't mind the fact that you got a meat bird, congratulations. He'll be full sized and ready for the table in 8 to 10 weeks.
Check out some pictures of cornish x and see if they don't look like your guy.