Bring the Emblazoned Battle Horn to Wyrmrest Temple and seek out someone who might be interested in assessing the potential threat.
The underside of the horn boasts an emblazoned seal with a hammer and lightning bolt. Something about the horn seems extremely out of place on a Magnataur.
You will receive: 5 30 + 250 Wyrmrest Accord Reputation
It is indeed strange for any magnataur to carry an item such as this... and very concerning. I am glad that you have shown this to me.