Headless Horseman's Steed. Despite having done the Headless Horseman since he came out, genuinely killing him over 2000 times when he dropped the mount himself, and having killed him every week since they attached the Horse to the daily satchel, I still have yet to get one. On the other hand every single person I was running with when the mount dropped off of him got it and even got it on some of their alts. We had 7 of us who switched in and out to give additional attempts at it each with 4-5 alts. On average we would kill him 57-102 times a day, and we saw a grand total of 6 Headless Horseman's Steeds drop and I won 0 of them.