Poison

Poison is a hazardous and harmful element that first appeared in Worms Armageddon. In Worms Armageddon, Worms World Party, and Worms 3D, poison can only be created by poisonous weapons or Sudden Death (although in Worms World Party and Worms 3D, a Wormpot mode called "Energy or Enemy" poisons every Worm on the landscape), but in Worms 4: Mayhem and Worms: Ultimate Mayhem, Oil Drums create poison instead of fire once destroyed, and in Worms Revolution, and Worms Clan Wars, certain Landscape Objects will emit poison when force is applied.

Effects
When a Worm is poisoned, its health slowly decreases every turn, usually 2-5 health points being taken away. If a Worm is not cured soon, it will not die, but its health will eventually be reduced to only 1 health point, making it extremely easy to kill. Your Worm can be cured from poison if you collect a Health Crate, use an Icarus Potion (Worms 4: Mayhem and Worms: Ultimate Mayhem only), collect certain types of Mystery Crates (Worms 4: Mayhem and Worms: Ultimate Mayhem only), or drink Red Bull (Worms 3D only).

Poisonous Weapons
There aren't many poisonous weapons in the Worms series compared to standard weapons. The most powerful poisonous weapon is the Indian Nuclear Test, since it poisons every Worm on the landscape (including your own Worms).