One man's LEGO is another man's treasure, and what better way is there to guard your grand stash of colored bricks than by using the bricks themselves as a weapon? The Thriller Automatic and Thriller Compact are slide action crossbow pistols with cocking and chambering mechanisms that are almost completely made out of LEGO. Martin Hüdepohl, a German designer and the man who built this amazing monstrosity, has a video of the gun in action. Pew pew!

Instructions on how to become your own LEGO arms dealer can be found in Hüdepohl's book, LEGO for Adults. The book features construction plans for the two weapons, detailed operating instructions, and a Thriller Automatic mini poster. According to the website, only 1,050 copies of the book were made because of LEGO's rules against using their trademark in connection with guns. So grab the book quick, before you're on the losing end of a LEGO showdown. [Xubor via Boingboing]