A Kinoshimobe (kee-noh-shee-MOH-bee; Jap. 木のしもべ "The servant of the tree") is an elemental being that appeared in "Tree People". They have a symbiotic relationship with Jubokko trees.
Kinoshimobes are towering humanoids made of plant materials with chlorophyll for blood. When they attack, they do so by ensnaring their victims with vines before having one of the said vines deliver a killing blow via stabbing. They can make vines shoot out from their hands, as well as from their feet. Despite being slow-moving creatures, they are quite strong, able to easily life a fully grown man. Bullets do little against them, as their bark-like outer layer provides them significant protection. However, sharp weapons, such as a labrys, can injure them significantly, as Nick dealt one Kinoshimobe a significant wound with just one strike to the upper torso area. When a Kinoshimobe is dying or heavily injured, it will be taken into a Jubokko tree, resulting in knots in the Jubokko tree's bark that form the likeness of the Kinoshimobe. Unlike other victims of the Jubokko tree, this image is animated and sentient, able to move its eyes. However, it is unknown if the image is animated when the Kinoshimobe is dead, or only when it is badly injured.
Kinoshimobes are protectors of Jobokko trees and fiercely safeguard the surrounding approximate five square miles. Anyone caught violating nature are at risk of experiencing a Kinoshimobe's wrath. Kinoshimobe do not discriminate between accidental (a leaking car) or intentional (poaching, dumping toxic waste, etc.) violations against nature. However, they do discriminate between individuals in groups and will only go after the particular individuals in that group they deem responsible for harming nature while leaving the others alone. Once they have identified a target to attack, they can not be reasoned with. When they have killed their target and dragged the body back to the Jobokko tree they serve, they will humbly kneel before the Jobokko as it takes in the body the Kinoshimobe has brought to it.
They appear to be most active at dusk and at night, while dormant during the day; this may be by design, as they are not particularly stealthy but are much harder to spot in the dark. They do not speak or express many emotions, but they do emit a low bass type of sound that resembles the deep creaking of a large tree.
As demonstrated by how one Kinoshimobe reacted to Nick's ability to defend himself, they do not expect their victims to put up much of a successful fight, if any, including Grimms. The latter may be the case due to the extremely low number of instances in which a Grimm has ever encountered a Kinoshimobe, let alone ever fought one.
There is insufficient information of the Kinoshimobe, considering these observations of Akemi Ando Araki are unreliable and opiate-addled. His findings detail the elusive solitary beings, and though other recorded accounts are exiguous, there is no testimony regarding its human form - if indeed it has one - and those captured are never seen again, lost to the Boscage for eternity.
(Information added by Sebastian and everyone)
When the Jubokko opened itself up and gathered the dead Kinoshimobe back into itself, we discovered its symbiotic relationship. And no Grimm had previously been able to make that connection. The Kinoshimobe takes those that harm the forest, sacrificing them to feed the Jubokko.