This papercraft is the Mjolnir, a fictional weapon that appears in publications from Marvel Comics, the paper model was created by Apocalipsis. It is the favored weapon of the superhero Thor. There is another paper model version here: Thor: God of Thunder - Mjolnir Free Papercraft.
Mjolnir is typically depicted as a large, square-headed gray Lump hammer. It has a short, round handle wrapped in brown leather, culminating in a looped lanyard. The object is based on Mjölnir, the weapon of the mythical Norse god. The hammer's name translates as "The Crusher" or "The Grinder."
You can download this papercraft template here: Marvel Comics - Thor's Mjolnir Papercraft Free Template Download