This is the first of three ring drops I saw on my various Headless Horseman kills. It's a healing ring. I saw it a lot.
This ring also dropped quite often for a group with only one caster DPS in it.
We had two physical DPS and one hunter when we killed the boss this attempt. The ring only dropped that one time, so I passed to the hunter. Not only do I have better rings for me, I'm married to her.
We were rotating alts in pretty heavily (I think we ultimately killed him at least 9 times) and yet we pretty much always got the caster or healer rings. This is my DK and a pally tank engaging.