Disclaimer

This prank is called “Rattlesnake Eggs”. I've also heard it called “Dead Killer Bee”.

It requires an envelope, wire, rubber bands and a flat washer. The wire is fashioned into a U or curved shape so the rubber bands can be secured with a washer in the middle.

You wind up the washer and rubber band assembly and put it into the envelope without sealing it.

You can also write Dead Killer Bee Inside or Rattlesnake Eggs Inside on the envelope. You can even put a large WARNING! on the envelope too.

If you have assembled it properly when the envelope is opened the flat washer will spin inside the envelope and make a buzzing or rattling sound. Hopefully scaring your victim a little.