Monkey Crab

It totally slipped my mind that I never posted the text for this anywhere. So here's another Diyu entry that never officially came out (the picture was posted in the collage on DeviantArt however).

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Monkey Crab (Pithecocaris gigacancer)

Diyu is a three-dimensional environment and life clambers and crawls over its floor, its walls, the ceiling; nowhere is that more pronounced than the fleshy bowels of Avīci, the deepest pit of Diyu. The dense mycelium coats every surface often several feet deep, forming a sponge-like coat over rock in which countless life-forms coil and writhe unseen. More than a few spelunkers of Avīci have met their end after being caught by something dwelling within the root-like network of hyphae; predators of Avīci are no less terrifying than any elsewhere in Diyu, but evolution has been flipped on its head and conventional Diyuian 'norms' (for lack of a better word) occupy far different niches than they do elsewhere. The chericarians of Avīci are not the aquatic tentacled predators of Diyu's subterranean seas, but terrestrial fungivores which retain simple antennae. The largest inhabitant of Avīci is the chericarian capsule bug, but it is not the only species. The monkey crab is a much smaller species and one of the few Avīci endemics to successfully proliferate into the Greater Diyu environment.

It would be difficult to think of a more different animal that could be a close relative of the immense elder crab (with 'close' being a relative term, considering they branched off some four hundred million years ago); while the elder crab is a massive pelagic carnivore with long facial tentacles, the monkey crab is a small clambering fungivore with long hooked appendages for climbing. It reaches up to twenty centimetres in length, but with its legs sprawled out it can be more than a foot in diameter. Despite having a hard exoskeleton, the legs of the monkey crab are unusually flexible, being able to swivel nearly a full rotation at their base and bend to face backwards with ease. As a result, the monkey crab is one of the best climbers of any Diyu animal, far exceeding the glacial pace of other ceiling dwellers such as pebblers. They seem to grapple upside-down just as easily as a normal animal might locomote on flat ground, but true brachiating has been reported, although it is less common. The sight of what amounts to a giant insectoid swinging overhead with the same competence as any real monkey is surely a surreal sight a mile beneath the surface of the Earth.

There are numerous other adaptations for such a lifestyle present on the monkey crab which greatly differentiate it from the closely related capsule bug that it coexists with. Unlike the capsule bug, their eyesight is quite good in comparison, a necessity for a small clambering animal. Its front pair of eyes forward, resulting in crude binocular vision, while the back-pair face to the sides, effectively giving the monkey crab a nearly spherical field of vision. Compared to the vision of some other animals, such as that of jetsquids or humans, their vision is not very special, but within Avīci, most animals do not even have eyes at all, and they rank among the most visually competent in the deepest bowels of the Earth. A pair of small hammer-shaped projections between the head and abdomen similar to insect halteres act as balancing organs to keep the body spatially oriented while swinging about, as they often spend long periods upside-down or clinging sideways to walls. A thin skin-like membrane stretches between the appendages, which is normally hard to notice, but when jumping the membrane unfurls a bit to reveal the prominent webbing used to help slow falling speed and decrease the chance of injury when leaping. They can also cover some horizontal distance when leaping from a great height through this method of parachuting, although its nothing compared to the flattened bodies of velvet rugs or wings of shenqi in terms of gliding prowess. As a consequence, the monkey crab's ability to walk on flat ground is reduced, with their large curved claws resulting in an awkward cumbersome stride.

Monkey crabs, similar to both its namesakes is very generalist in its diet, although most of its diet is made of soft fungal mycelium, this being one of the most common potential foods in Avīci. The hard-shelled fruiting bodies are usually ignored or discarded outright, with hellrash hyphae being preferred among shelled mushrooms; certain bladder fungi such as pusballs and cave pancakes which commonly grow on the ceiling or on the walls are particularly relished. Small, soft-bodied invertebrates are the most common animal matter consumed, and this is usually smaller snail-worms and harpoon worms; arthropods such as trilobites and small pebblers are a lesser component. Monkey crabs are not attracted by carrion, as most carrion attracts more aggressive carnivores that would prey on monkey crabs, and most carrion also occurs on the ground, which the chericarians try to avoid extended contact with. This adaptation to a climbing lifestyle is believed to be anti-predation in nature; major predators within Avīci are either terrestrial and/or sedentary and so by being a relatively quick animal that avoids the ground, it can avoid most of Avīci's predators. Healthy adults suffer only incidental predation in Avīci, mainly from individuals that fall to the ground, or the occasional velvet rug. Younger monkey crabs, being smaller and less experienced, suffer a far higher mortality rate; the barb worm has been known to lunge through the spongy mycelium to snatch juveniles straight off their parents' backs, but this is uncommon. Outside of Avīci, predation rates on adults are much higher, and so they are much less common in Diyu outside of Avīci.

The monkey crab produces one (or less commonly, two) offspring in a single brood, with the time between each brood varying from eight to thirteen months. The nymph is pale and weak for the first several days of birth and clings to its mother for protection, but as its carapace hardens, it will soon have the strength to clamber along with the rest of its group. Monkey crabs, similar to their close relative the capsule bug, but unlike chericarian species from outside Avīci, travel in herds for protection. These number around dozen, with most groups being ten to twenty adults strong; troops found outside Avīci tend to be larger due to the greater availability of resources, and a few are known to exceed forty animals in number, but this is rare. Care of young is communal, and should the nymph’s parents be killed before it reaches maturity, another adult (male or female) may adopt it. Young monkey crabs can feed themselves from birth, but receive safety and experience from their parents, and often help care for siblings of later broods. Monkey crabs mature within a few months, as they are birthed large and well-developed, but generally remain with their parents for longer. Monkey crabs are monogamous, but infidelity rates among them are high; this may have resulted in their communal care, as the chericarians can never be sure which other crab a nymph may be related to.