Physics and the general laws of reality do not work in the same way in the Parasite World as in the Prime World. The Parasite World exists in multiple planes, all of which can be accessed through various means from within the dimension. These planes - or Layers - are not planets per se, and do not necessarily work on the same rules as Prime planets as such. Geography, visible stars in the sky (if any), and other core factors of Prime planets can be entirely alien and, by human standards, nonsensical. Some Layers - particularly those near the "top" of the Parasite World - can resemble the Prime very closely, aside from the ubiquitous presence of alien fauna and magic. Other Layers can form alien landscapes such as worlds of endless canyons, perfectly flat steppes, seemingly-naturally-occurring Dyson Spheres, or bottomless oceans.

Every layer of the Parasite World contains unique ecosystems and creatures. The one commonality between all the layers is that the majority of fauna and a good chunk of flora native to them are succubal or incubal in nature.

Despite the usage of terms like "top" and "bottom" to refer to the Parasite World, the world's layers don't work quite the way this naming scheme implies. Access points between layers do not cleanly lead from the top of the world to the bottom in sequence, and individuals who fall into the Parasite World are no more or less likely to land in the deeper layers than the upper layers.

The "topmost" layer of the Parasite World, a swamp world of unknown size that appears to adhere to most of the basic laws of physics of the Prime, up to and including having a normal curvature like a planet would. Denizens of the Parasite World know Nadayal to be poor in metals but rich in magical reagents and energies.

The layer is so named by the hydromels, the most well-known sapient natives of the layer. They are not, however, the only natives. Several other native succubi and incubi species live in the layer as well, most notably goblins, kobolds, and ambrosians.

A species of non-sapient arachnid succubi native to Nadayal. Acorn Bugs are voracious and indiscriminate hunters who will happily hunt males of any species, sapient or unsapient. They will even hunt other succubal and incubal feeders, though non-succubi are their preferred prey.

Named for their females' acorn-like appearance, acorn bugs are in many ways similar to Prime World ticks in appearance, albeit much larger. Adult females will typically range from 92 to 122cm in length from end to end, while males measure from 76 to 92cm long on average. Hatched from clutches of 4-6 eggs, acorn bugs will usually measure 15-30cm long immediately after hatching.

Acorn bugs are ambush hunters who feed primarily on semen, typical of succubal species, though their hunting methods differ greatly between their two sexes. Males will hunt using web traps and live in groups of 4-6, while females are loners who ambush and run after prey.

All acorn bugs possess a stinger used for self-defense.

Acorn bugs are related to Nadayal's native goblins. They are (roughly) to goblins what chimpanzees are to humans. Though while certainly intelligent for giant arachnids, acorn bugs are not brilliant toolmakers and tool-users like apes.