So possibly our biggest surprise at the Potter Party last weekend was Tiny Tim, the life-sized thestral in the back yard. Yes, thestral. You know, the undead skeleton horses that can only be seen after you witness someone dying? I mean, HOW FESTIVE DOES THAT SOUND. via Pottermore It's all Home Depot's fault, of course, since they were selling life-sized horse skeletons for Halloween. We weren't about to drop $200 for it, though, so we waited 'til November 1st, called every Home Depot in the…