I fought a few groups of gnolls in Antonica and after the first one died, the rest started running away. I chased after them, trying to hit them, and eventually they just disappeared into thin air.
The most memorable time was about a week or two ago, I was fighting a group of gnolls just North of Gnoll Keep, near a little tent and shortly after I engaged the encounter, all three of the gnolls run back to the tent and "appear" to be conversing with another group of gnolls. All this takes about 5 seconds or so, then BOTH groups run back to me and start attacking me. Before I realized it, bears, and wolves had aggroed onto me as well. I was surrouded by hoards of mobs. I yelled and ran away as fast as I could and was lucky to live.
I thought maybe a GM was messing with me, though I considered the possibility of a bug, either way curiosity got the better of me, so I went back to the same camp and witnessed gnolls running away, as previously mentioned, and then the second weirdest thing.
I engaged 2 gnolls, that were green to me. They were exactly identical to all other hundreds of other similar gnolls I was killing before, except these ones were very tough. How tough? Let me give you a basis of comparison. I can engage two groups of green heroic gnolls at the same time, and though it will be a tough fight, I will come out on top. I used every resource I had, including Lay on Hands and barely killed the first green gnoll. Out of Power and low on health, I didn't have a chance killing the second one and eventually had to run away!
I have never seen anything like before or after than incident. Somehow, something gave those two green gnolls a lot more strength and hp than they should have.
Not sure what is causing these things to happen, but it is weird.