There are also "time bombs" (who automatically kill the people who kill them or either start or finish a vote against them) and mediums (who receive messages from deceased players). Probably a few others I'm not recalling off-hand.
My take on last night was that the dragon (likely commanded by Daneris) was the serial killer, and they just happened to target a villain. I also figure that the hero that the villains targeted was either a two-kill, or they were protected last night. Either way, we got lucky last night.
I was gonna let the discussion play out a bit, but I've got to work a 12-hour shift tonight, so I'm getting my vote out of the way now. And while I'm in favour of not killing anyone off in the first day, we can't really afford to go two days without voting somebody off. And photo fox's reasoning seems as sound as anyone's, so....
5 to DL Hanged Man (photo fox, Drogo, Athena, SVNBob, Spruce), 5 to defend the wall.