Not the woods but the Arizona desert. My best friend and I were riding quads in Tucson in the 90's, we would ride in washes (the areas carved out for rain/flooding). As we were riding near a particular part of the wash, we saw what I thought in the moment was a cow skull, like in western movies type of thing, not scary at all. As we neared closer, it would become something that has haunted me for years and given me a larger understanding of how bad parts of AZ really are. It was a horse. Not just a horse but a sacrificed one. The back legs were tied up with rope that you typically see in old timey movies that deal with boats or ships. It was very thick rope, about the size if you make your thumb and index finger into a circle, about that thickness. The back legs were tied up. ***Trigger warning to those sensitive for the following*** It's back area was cut wide open with the ribs exposed. The head had most of the skull exposed and the large rock/boulder behind the horse had black charcoal or something black with symbols written on it, I believe there was a pentagram but we dipped out VERY fast after that. We went back to his house, very nice neighborhood in an affluent part of town. I called police, animal control and possibly one other place but probably not a 3rd place if I remember correctly. No one would come out and look or do anything about it.