Hello,
I’ve tried to figure this out, sorry.
If you log onto my Horde druid- Acero, there’s a very large musical horn on my back. I would like to have it removed.
Crazy and silly problem I know but if you log onto my Horde druid- Acero, you’ll see it.
Thank you kindly.
Well if its a buff theres 2 ways to get rid of it enter a arena/bg or take off all ur gear fly realy hi and dismount death should clear it.
I had the same thing happen to me 
It’s part of a quest you’re currently on. I can’t remember which one, but it’s a newer questline. Try completing some of the quests in your log and it should go away.
The quest line involving that Horn starts with this quest:
It ends with this quest:
If you are still unable to remove the Horn after completing the quest chain, then you can go to the Maw into the River of Souls to find the Projection of Ve’nari and she can remove it.
Okay, so looking over your Druid’s quest completion – they left off in the middle of the chain and have not completed this quest: