We met Jack Skellington & Sally in the lobby at AOA when we arrived on 8/20, and saw them greeting there a few other days throughout our stay. We asked the concierge about it and she said they were "getting ready" for Halloween, and staff at AOA didn't even find out until the morning of that they would be there that day. My pictures aren't very good because we'd just gotten off the plane & DD2 wouldn't stand still (although she did go up and talk to them!) but it was a really cool surprise to start off our trip.