From Goblin Group
Thorn mist is also know as a gray mist or simply an Evil presence. It is a gray low ankle-deep mist which seems to travel in clumps. Exposure usually results in small thorn-like scrapes and cuts. Swinging violently at the mist seems to move it away.
The mist has been observed to flow both up hill and down but particularly attracted to climbing vertical slopes such as tree trunks and walls.
Coldario Staffs, basically a long smooth pole with a sharp point planted in the ground point up, have been seen to reasonably block and dissipate the mist. The mist seems to be first attracted to the staff. The mist then climbs to the top and dissipates into the air above.
Some unnatural creatures have been seen to transform into thorn mist after being slain.