Black Raven Dragoons

If you do the old quest chain for the headless horsemen you will get that summons plus the daily summons ontop of that just did it today as with a few others that wanted to know if you could do that have 7 tries at him =D enjoy

I've always been one for overkill. If you want more in depth info on the event and some of the side quests, here you go:

http://www.wowwiki.com/Hallow%27s_End