This is some Batman and Joker fan art from Daeyoon Huh
Huh is a concept artist and he composed some digital art of Batman and Joker, along with a sculpted version of a Joker bat helmet. Check out a synopsis about the helmet and the images below.
"I was inspired by ARKHAM KNIGHT. I made a character infected by joker virus who want's to play with batman. He found abandoned bat suit from wayne tower. He destroy Arkham city and uses reversed Bat logo to call the Batman. Analog Clay + kit bash project. didn't use any 3d prints. I use car paint. Purple color is difficult to capture. real color is much redish. Scale is 1:1. I took 14 week."