This really detailed work is papercraft made by the Japanese graphic designer Shunichi Makino. For years he has been crafting sci-fi creations out of paper, and in his collection you can find Star Wars characters, the Terminator, Iron Man and others. Makino has also made it possible for everyone to download the patterns in PDFs so that you can cut it and built the models yourself if you want.
It’s a great hobby to have, and it makes it more special to have models of paper instead of plastic. Paper has been used by other artists that have made realistic sculptures out of it.