Nokkers

Knockers (ノッカー) are unknown creatures that were created to impede Fushi's progress in preserving the world. The Beholder named them "Knockers" because they "Knock on the doors of paradise, seeking its destruction."

Description
Knockers are creatures that were created by an unknown being for the purpose of hindering Fushi's progress in preserving the world. The Beholder also said that they have been designed to weaken Fushi by stealing the vessels (bodies) he has gathered.

A Knocker's main form resembles long, presumably sharp, vines. However, they adapt to their environment and take on various other forms - forms stolen from Fushi. When in the forest, the Knockers took on the appearance of vines and leaves. At Rynn's house and on Jananda, it took on the appearance of rocks.

Abilities

 * The Knockers have the ability to steal Fushi's forms, along with his memories of that form. For example. when the Knockers steal March's form from Fushi, he is completely unable to remember her. He isn't even aware that anything was stolen from him.
 * They adapt to their environment and are constantly studying and learning about the world around them. When Fushi first encounters the Knockers in the forest, it is made up of vines and leaves. The next time he encounters one on the island of Jananda, it is made up of rock.
 * The Knockers are able to control a person's body, whether they are dead or alive.

Hayase's Knocker
A name referring to the Knockers that has been with Hayase since she left Jananda. This Knockers first appeared to her on the boat Fushi left her on in the middle of the ocean. Somehow, this Knockers attached itself to Hayase's arm and has been passed down her bloodline ever since.

This Knocker is clearly different from the average Knockers, capable of understanding its host and appearing to have a mind of its own. Whether the ability to understand a host's body only applies to Hayase and her descendants is currently unknown. It is also unknown what exactly this Knockers' goal is.

Abilities

 * This Knocker can communicate with its host body, but act on its own when in danger. This can be seen when the Knockers attacking Tonari broke Hisame’s arm and finger to run away.
 * This Knockers' main purpose aside from destroying other Knockers is to sense and track Fushi.
 * Kahak can utilize this Knocker's power, giving him superhuman strength.
 * In chapter 78, This Knockers writes to tell Fushi about the Knockers' objectives and tell its friend's (other Knockers) locations.