Normally when you see the words "egg" and "prank" in the same sentence you'd be expecting to see someone (or something) get covered in egg yolk -- especially when the egg in question happens to be balanced on a man's head.
But if there's one thing the British guys who recorded the prank above should be commended for, it's their originality. Their colleague Jeff -- who's the victim of the egg balancing scheme -- may have suspected something, but he definitely wasn't prepared for the final outcome.