A snipe hunt is a prank that involves getting someone to go on a wild "hunt" for something that doesn't exist. For example, some people may tell you that they need you to try and catch a snipe. They might say they can be found in a certain area and give you a bag or bucket and tell you to try to catch one. You may search and search but you won't be able to catch a snipe because they don't exist! It's all a silly prank that somebody is playing on you.