As the Spirit Tree represented the light and is inhabited by those spawn from the light emanating from the power of "God", the Qliphoth is the tree's natural opposite as its residents are spawned from the impure darkness born from nightmares and humanity's subconscious evil thoughts.
Slan used her powers as a God Hand to convert a wooded area into a corrupted place with her od while opening portals to the Qliphoth for its denizens to take residence within a small network of caves. Slan appears to Guts in the Qliphoth by embodying the intestines of slain trolls when he reached the central point of the caves' depth.
The only dangerous inhabitants of Qliphoth's fell ecosystem are the only humanoid ones, trolls and ogres. Qliphoth's other lifeforms resemble non-sentient creatures like arthropods and mollusks, but most of them are entirely composed by human parts (sea anemones with human fingers for tentacles, head-like trees with a beard of roots, horseshoe crabs with human faces on their shells, and the like), while the rest are even simpler critters like slugs and worms. Despite their disturbing appearance, some of them simply gazed at Guts' group with mild curiosity, while others just kept to crawl/fly/swim around without doing any harm. In a troll lair, besides a few spider-like predators, there are bottom feeders that gnaw at the bodies of the trolls' victims and simply ignore living humans.
- The term "Qliphoth" or "Qlippoth" is used to represent the manifestation of evil or impure spiritual forces in Jewish mysticism, usually compared to the "Sephiroth".