The Side Winder mechamecha from NCsoft's Exteel shooter game, designed by Just Paper
Download is on the bottom left corner of their page (see pic below), click the first option right under where it says "Exteel Zone". Then you'll get two files, one is the 23 page papercraft template and the other is a 12 page instruction manual, both size is 88MB.
Mecha Papercraft - Exteel Side Winder