Poison Gas

By stepping on one of these you will take 5 earth damage and get the Poisoned special condition for 100 hitpoints (totaling 105 damage). The poisoned condition ticks for 4 turns of 5 damage, 5 turns of 4 damage, 7 turns of 3 damage, 10 turns of 2 damage, and 19 rounds of 1 damage. Its effects can be cured by the Antidote spell or Antidote Runes, and the gas can be removed by using a Destroy Field Rune on it.

Looks the same as Plant Poison.