It's an extremely rare species of centipede, the Beige Frontrunner.
When you look at the part that resemble human pelvis, you notice something entirely unprecedented across the entire kingdom of Animalia -- a hole! Animals don't just make holes. They're hard to make, they don't provide any benefit, and they become a liability when the creature overlooks a tree branch at just the wrong height while they're running away. Closer inspection reveals the truth. It's a pair of chelicerae! Knowing this, we can finally figure out how the entire creature's body plan.
So... since the pelvis is actually a pair of chelicerae, then what looks like the coccyx must be the creature's head. What looks like the head must actually be the tail, and the rest must be limbs! The back pair and the front pair are extremely enlarged, while the rest are shorter and serve purely as mimicry. Some of them close at the front to make the appearance of a rib cage, while some are much shorter without much mobility.
Heck why, I hear you ask?
In the long past, the creature had two pairs of enlarged limbs that served primarily as defense. The creature's unusual posture - bipedal using the front pair of limbs - has evolved from how the creature used to escape from predators. You know, 20 pairs of limbs are hard to coordinate while you're trying to hit your top speed, and lifting on your hind legs requires them to temporarily move faster than your center of mass and then slow down. The Frontrunner's ancestors would instead just push against the ground and become upright in the other way, sacrificing the temporary boost of vantage point for a quicker departure from the impending doom.
The hind pair of limbs grew longer and stronger to make the transition to upright even faster, while the front pair grew longer and stronger to provide speed during the upright phase. Eventually the creature learned a new purpose for the hind legs - as manipulators, to grab fruit from bushes and trees. This, along metabolical benefits, pushed the creature to grow longer and thinner. In the mean time, the rest of its legs just ... stayed the same. some grew slightly longer to serve as secondary manipulators - function now lost - while some shrunk to just decorative stubs. The creature did have to grow thinner as it grew taller because otherwise it wouldn't be able to support its own weight!
Then come humans. A couple thousand years ago, one group of monkeys endemic to the Red Sea region has decided it would be a smart idea to start collecting their dead to one place to reduce the risk of being detected by predators - and Beige Frontrunners have quickly discovered a new survival strategy. Because they already resembled the skeletons of those monkeys, the Frontrunners that chose those boneyards as their resting spots found themselves mostly ignored by their usual predators. When the predators began to figure things out, Frontrunners had to improve their mimicry. It was not too long before those ridiculous bulges on their tails began to evolve, as well as the coloration and unusual head structure. The eyes finished their migration to the back of their heads. Their main limbs' tarsal claws grew longer for mimicry, and they even developed local coloration that resembles the fingers of a human hand, and a stripe that mimics the gap between the radius and ulna...
As to why Frontrunners cease to function when their tail decoration that resembles the human skull gets removed ... I would also lose my mind if somebody decided to just chop off my reproductory organs!