Now that you've seen some crazy wingsuit BASE jumpers, check out five more of the weirdest extreme sports ever. They include underwater hockey, volcano boarding, wife-carrying, and lots more. Who knows? Maybe a well-known professional athlete may make the transition to one of these sports in the near future. Continue reading to see them all.

Sure, you could argue that this AR-15 semi-automatic rifle only features a 3D-printed lower receiver, but the fact of the matter is that the weapon fired successfully. That's right, a 3D-printed lower receiver was tested to failure shooting real bullets. Continue reading for a video and more information.

Here's another fascinating look at Costa Rica's transparent glass frogs. The image above was captured by photographer Nic Reusens with a pane of glass and a twin diffused flash to capture the natural effect of the stunning animal. Continue reading for a video, more pictures, and additional information.

Klipsch's IMAGE S4 Noise-Isolating Headphones are currently being offered at only $34.99 shipped, originally priced at $79.99. Its "enhanced bass and superior noise isolation ensure clean, professional sound, while the innovative eartip design and angled nozzles provide a comfortable fit for long-term wear." Product page. Continue reading for an unboxing video.

That's right, the Mercedes-Benz Museum, an automotive museum housed in Stuttgart, Germany, currently houses the world's largest artificial tornado. The building's design is based on a unique cloverleaf concept using three overlapping circles with the center removed to form a triangular atrium. Click here to view the first image in today's viral picture gallery. Continue reading for a video of the tornado in-action.