Uh, I assumed psycho!cannibal from the large amount of blood, loud *crunch*, amount of blood, presence of blood around his mouth like he took a big bite of flesh rather than sucking from a small wound, lamb references ("Silence of the Lambs" if you don't know who Hannibal Lecter is), and suspicious close-up of the hamburger immediately after he smiled creepily and said "good luck" with getting his family/friends (or their bodies) back.