Exclusive to: 
“I think I'll stay away from that.”
“Nature is so gross.”
“Cowardly hole!”
“The ground belches death.”
“THE SOIL ITSELF IS TOXIC”
“Keep your distance. Airborne toxins spew out in regular intervals.”
“I think I'll give that a wide berth.”
“I can see it just fine from here... No need to get closer.”
“An alluring landmark of lurid effluvium.”
“The gröund belches with sickness!”
“Yikes! The ground is farting!”
“Gag!”
“I smell trouble...”
“Th'worst kind o'hole.”
“IT BELCHES FORTH THE YUCK”
“Dirt is burping”
“Smells like a trap. Also smells like a sewer.”
Poisonous Holes are naturally occurring objects present in Tidal Marsh biomes in the Shipwrecked DLC.
Approximately every 3.5 seconds, the Poisonous Hole will release a toxic cloud of gas, which will Poison the player or any Mob standing too close when this happens. The player can protect themselves from being poisoned by Poison Holes by wearing a Particulate Purifier. WX-78 does not require a Particulate Purifier for protection, since they are immune to Poison.
When a Poisonous Hole is dug up with a Shovel, it will be destroyed in the process and has a 50% chance to drop either a Venom Gland or Rot. Once a Poisonous Hole has been dug up, it will not return.
Gallery
Poisonous Holes as they appear in the Tidal Marsh.
Mobs being too close to a Poisonous Hole will be poisoned immediately.
