Played Quake recently? Or listened to any Trent Reznor? This man's insane, semi-automatic nine-inch nail gun will make you want to do both. That and also eat some melons.
From the same mind the brought us a lovely and inadvisable 3D-printed cornstarch flamethrower comes this spike-sling monster, which can apparently be made from the sort of debris you might expect to find in a post-apocalyptic landscape. Inventor Ivan Owen doesn't share any of the specifics on how he created this monstrosity, which is both a little disappointing but probably also for the best.