For this to work you must look at the wolf with one of your eyes covered up (or through a camera lens.) His head, which is folded to be inverted, will then appear to 'pop' forward & spring to life as your brain readjusts & your eyes see a convex image instead. Slowly move around to see him following your movements!
Just print the downloaded image onto regular A4 paper, follow the provided instructions to assemble him together. You'll only need some scissors & a little tape or glue to see this fantastic illusion for yourself.