The Holy Hand Grenade is the most powerful grenade in this game. It will make a lot of land damage and it sometimes will send you flying away. Its normal damage is 80, but it can inflict more than 100 damage if you use it properly. Before it explodes, there is a voice that says "Hallelujah" and it explodes. Worms that will be hit by this grenade will usually fly while screaming, "No!!!".
The Holy Hand Grenade is actually from the film Monty Python and The Holy Grail, which the grenade is used in the film to vanquish the killer rabbit guarding the entrance to the Cave of Caerbannog. This grenade later appeared in the Worms series games.