Holy Hand Grenade of Antioch

The Holy Hand Grenade of Antioch is the weapon used in Monty Python and the Holy Grail to destroy a killer rabbit. The instructions for its use are in the holy book of Armaments. Particularly important is the counting to three after the pulling of the pin (complicated by King Arthur's mental block on counting).

The Worms series of computer games features a weapon called the holy hand grenade, which - unlike the other types of grenade in the game, which have variable-length fuses - is always set to explode three seconds after it is thrown.