We had someone DC for long enough in our raid tonight that he had to wait a 1000 players queue. so I was derping around before Galakras while we waited. While I was going around with water walk, this happened.
http://i.imgur.com/vunuS8B.jpg (picture is too big)
Basically, I randomly got a debuff called "Fire Pit" that deals 100,000 fire damage per second. I would only get it in a very specific area and couldn't find another close area to get it again. There is nothing underwater that would hint at any pit of fire of some sort.
Just thought I would share as it's quite odd. A dev misclicked when trying to put a fire pit and then was like "meh, no one will ever go there"