Tail Nail

The  is a melee weapon available in Worms 4: Mayhem, and can be used to pin down a troublesome wriggler, preventing them from creeping to safety, fetching an important crate, or moving into an opportune firing position. When used, your worm bashes an enemy on the head with an enormous wooden mallet, burying them in the ground and preventing them from moving. The only means of escape for the victim is either to use a Teleport, or an explosion carves out the piece of terrain that they're currently rooted in.

Even if a worm is rooted by the Tail Nail, they can still rotate in place and operate weapons as normal. They will not, however, be able to use certain utilities, such as the Jetpack or Icarus Potion.

Despite the name, no actual nails are used in the operation of this weapon.

This has to be one of the cruelest weapons in the game. Once this has been inflicted upon an enemy they are stuck, and you can use this to wear them down.

The most effective use of this weapon is if you can lure an enemy worm to a very difficult part of the landscape and then Tail Nail it in place whilst you then set about the rest of its team.

Also having an enemy worm stuck in place gives you the opportunity to practice pulling barrels and mines towards them using the Ninja Rope. Pulling barrels around a nailed worm stops them from trying anything silly as they "might" blow themselves up in the process. This also gives you the chance to cause maximum damage using a low damage weapon!

Weapons to avoid using against a nailed worm are things like the Fire Punch, Prod and Baseball Bat.

Usage
Simply select the Tail Nail from the weapon menu, approach an enemy worm, and press the fire key.