5 hearts on mine - 2 neck, 2 left fore leg, stomach.
I killed this one, but he was the second version I found.
My first "attempt" had those five plus a third on the left foreleg and one on the rear left leg. That Ur stepped on my Arisen at the start of the fight, and then shook my Arisen off from altitude. While the fall didn't finish the job, Ur promptly stepped on him again and that (as they say) was that.