LOL Weird Bug

Some of you have seen some strange yellow bubble react like a steam in a infinite way in the air during a battle? its not a disturbing bug but a funny one. I was so much attracted by this that I have fail my fight lol

i give you a screenshot later I will post the video

Finally the video :

My only theory is probably that was a Gargoyle Tower there and one of my Pyromancer have fart just close of it. The mix of gaz and lava have create a spring of bobble in the air

LOL its funny but totally non sense lol but now the real explication :

 

I’ve had the gargoyle towers keep “brewing” after being destroyed, but it’s not bubbles on mine, it looks more like a sparkler (fireworks). It doesn’t hurt anything, but i wasted a blizzard on it once to see if it would go away.  Nothing…