Billy the Jigsaw Puppet

"Hello what's-your-name. I want to play a game. Here's what happens if you lose. The device you're wearing, which I rang up from RadioShack, is hooked into your upper and lower jaw. When the timer in the back goes off, your mouth will be permanently ripped open. Think of it like a reverse bear trap. There's only one key to open the device. It's in the stomach of your dead cellmate. Better hurry up. Live or die, make your choice!"