Spider monkey

My animal is the spider monkey. In the picture, the before monkey is swinging in a healthy, green tree. In the after picture, the monkey becomes an actual part monkey/part spider animal. In the after picture the monkey is beneath the rock, for defense and hiding from predators. It is a desert/arid climate with a dead tree and lots of rocks and sand. Obviously, this is a result of deforestation. This climate is a few hundred thousand years after present time, so the tree in the picture had survived for a long time. There are bugs around the habitat for the monkey to eat, who also lives under the rocks. One monkey when the deforestation process was happening was randomly born with 6 limbs, and then a few thousand years later one with 8 limbs. They kept their face and tail but were forced into the arid desert.