Exploding Chocolate

Spy gadgets in World War II: Exploding Chocolate Bar.

This ordinary-looking bar of chocolate is really a German hand grenade. It's made of steel with a thin covering of real chocolate. When the piece of chocolate at the end is broken, a strip of canvas is pulled out. After seven seconds the bomb explodes.

Shown here is the Plain bar. For added shrapnel, get the bar with peanuts.