Welcome to the Popular Science March Madness bracket! We don't know much about sports--is that where you toss around a ball for a few years then strap on an orange vest and help kids across sidewalks?--but we felt left out watching our friends have all the fun. So we decided to build our own bracket out of something we do know a bit about: robots and drones. Below you'll find 16 of the strongest, fastest, and strangest land robots, and 16 of the strongest, fastest, and strangest flying drones. Your job: vote for your favorites. Big Dog or Cheetah? X47-B or the DJI Phantom? If you need a quick guide to what's what, go here.