Hello and thank you for taking the time to give me some advice or help. (Going back and reviewing I now realize I typed a lot) To briefly summarize what kind of creature I have designed, I took a shot at making an imp (sort of like the ones from DOOM 2016) biologically feasible. The best way I can describe it would be a creature that stands upright and on two feet, is both good at moving on the ground as it is in trees, possesses a thinner/lighter prehensile tail, and the main point of issue for me would be the fact that this "imp" possesses a pronounced snout, much like that of a dog.
With this being said, I do not want to sound lazy and just leave you guys with a brief description and let you do all the work, I spent some time grinding evolutionary biology of arboreal primates and the like, and here is a list of things that I found would be necessary in order to facilitate a lifestyle for this creature.
1: In order to remain predominantly bipedal, and upright, this creature would have needed to evolve or possess a strong spine or central column that can support the grunt of gravity. What I did, is give this creature a strong, yet flexible torso which is proportionally longer than that of a human. Sort of like a chimpanzee.
2: This creature, being of human intelligence, would need a way to manipulate/grasp around its environment, this would also be necessary for arboreal locomotion. (or climbing things such as mountain sides, rocky faces, buildings, etc.) What I did was give it hands more tuned for climbing, specifically longer,stronger, more flexible digits with non retractable claws, opposable thumbs and a far greater degree of motion in its wrist joints. The feet are much like a human's, but with a semi pronounced heel for bearing the weight of upright bipedal locomotion, but much like the hands I have decided to make the digits on the feet longer, stronger, and much more flexible, with claws and with a greater degree of motion in the ankle joints, much like that of a raccoon. Its feet, however, lack the equivalent of a thumb, like we see with chimps. Instead, it uses more its longer toes and greater degree of motion in the ankle in order to anchor its toes into climbing surfaces. Lastly, its tail is prehensile and lightweight, so much like a monkey or a traditional imp in folklore, it uses this in order to further adhere it to climbing surfaces while also maintaining balance in the creature. The tail is very strong, so it can support the creature's weight while hanging, but not so heavy and bulky that it would significantly affect this creature's center of gravity, so that way it could stand upright like a human without the tail's sheer weight and size throwing it off.
3: This creature's limbs would be more like that of a human's, so the hip joints and knees are relatively stiff and stronger like ours, so what would really be doing most of the flexibility and climbing would be the ends of the limbs, namely the hands and feet. This would give it the best of both worlds when it comes to terrestrial and arboreal locomotion. Because of this, the creature would have the equivalent of a rump to support such limbs, and a strong core to connect the lower body to the torso. (also the pelvic region) Its shoulders and upper chest would likewise need to be stronger.
4: Next, and the main concern of mine, is the creature's face. It has a pronounced snout, albeit not too long and thinner. (Much like the cover art for the original DOOM game, namely the demons holding on to doomguy) As I understand from my research, the main problem with this would be the fact that a snout or muzzle like the one I gave my Imp requires much more muscles to not only support but also to operate such a structure. Also, the neck bones need to be stronger as well, as there is weight added with this snout unlike our flatter faces. In response to this, and in order to keep its upright stature, I made the neck muscles and those which attach the head to the torso stronger and a bit bulkier than that of a human, also longer. These bolstered neck muscles, at least I hope, do not affect the balance of the creature due to the upper back muscles also offsetting this new weight, so stronger trapezoids and the like. Because of its snout, the muscles near its face which operate the jaw were strengthened as well. In terms of cranium space, this creature's brain, being demonic in nature, is formatted differently than a human's, so the possibility of less physical volume to support a larger brain is not something I really cared to worry about, as it is intelligent all the same.
5: Lastly, in terms of the creature's actual size, it is much shorter than a human, and of a much lighter weight as well. Their tallest would stand at around 5 feet tall, and they would weigh around 120 to 130 pounds at their absolute heaviest (while at a healthy weight) This, if I remember correctly, helps an animal move better against gravity, as they haul around less weight.
With this being said, I would greatly appreciate any feedback, even if it is merely "this would not work, and here is why". This is my first time posting here, so please forgive any egregious formatting on my part.
