What happens when you put dogfish sharks, which have been known to feed on octopuses from time to time, in the same aquarium tank with a giant pacific octopus? The aquarium's keepers figured the octopus would be able to evade the predator easily enough, so they didn't worry about it—until they started finding shark corpses on the bottom of the tank.
They put a camera into the tank and discovered that it wasn't the octopus that was in danger. The resultant video has been making the rounds on YouTube lately, in part because it's awesome, and in part because Detroit fans were hoping it would give the Octopus-loving Red Wings a chance over the San Jose Sharks. No such luck. (More octopus stories.)