"Servants" is the term used by the Trebhum to describe the foreign creatures that seemingly work for the Eternal Cylinder.
Description
The Servants to the Eternal Cylinder are all Bio-Mechanical in structure; hybridized with both mechanical limbs and functionalities, attached to humanoid-like organic matter. The machinery observed on the Servants appear eerily Earth-like in origin (vehicles such as cars, television screens, etc.) so it is possible their origins could be linked to Earth, but this isn't conclusive.
Outside of serving the "Whims" of the Eternal Cylinder, there doesn't seem to be any personal motivations, thoughts, or instincts that the Servants present, with the exception of a dislike towards all Organic life. Many members of the Servants also possess a "energy-draining" ability in form of a yellow beam of light, which can drain the abilities of the Trebhum.
Servant Types
From what little is observed of the Eternal Cylinder's Servants, only five of them had been properly identified and studied:
Cleanser
Cleansers are observed to be scouts for the much larger Mathematician. These bio-mechanical servants hold features similar to an old world Earth vehicle, but with several horns jutting out from the front to resemble a crest, two horns facing forward for frontal charging. Although its front end has wheels, its back end is mobile thanks to a set of large, muscular arms, with the torso seemingly attached to the seat of the vehicle.
These chimeric servants seem to only be used to eliminate any lifeforms that appear in the Eternal Cylinder's path (if proven too difficult to be killed by the cylinder itself, that is). Its "eyes" emit a blinding energy field that appears to act as an "antimutagen" to the Trebhum exposed to it.
Liberator
The Liberators is considered one of the most dangerous servants, only behind the Mathematician. These servants are more dynamic in its structure, with three metallic rings attached to what appears to be some form of chariot or engine, with a metallic spine replacing its spinal cord. A third ring loops around this spinal cord, though its function remains unclear. Compared to other servants, this one appears more humanoid, including a human-like face which is used as a visual organ.
Liberators are burrowing servants, lying dormant underground disguised as foreign matter on the surface. If organic matter comes too close, it will proceed to attack. It is capable of using a form of anti-gravity, to bring the victims closer to it, which are then vaporized in a intense energy field.
Mathematician
The Mathematician is the largest of the Eternal Cylinder's servants, standing taller than even the Great Gaaahr. Due to its immense size, other servants seem to follow its instructions as much as the actual Cylinder itself. Its body is surprisingly humanoid, having an almost complete human body with the exception of its bio-mechanical head, and two sets of legs attached to only one legbone, while the other leg remains as a singular one.
Not as much is known about this giant being, but it is capable of an anti-gravitational pull.
Unifier
The Unifier is a large bio-mechanical organism that strongly resembles the structure of a bacteriophage. The structure is made up of a male human torso, with mechanical legs and a diamond-shaped "head" attached, not possessing any arms. The structure underneath its body acts as a pulsar to release its energy.
The Unifier itself is considered blind, so it often relies on sound in order to examine its surroundings, and detect its targets. Upon capturing their targets, they're capable of emitting a huge electrical shock that will vaporize the victim, and destroy organic matter around it.
Witness
The Witness is considered one of the smallest servants to the Eternal Cylinder. This servant is only made up of two human-like hands, infused with what appears to be a sort of television screen, which it uses as form of a visual organ.
The being itself isn't dangerous, but it will send out an alarm if it spots a threat, signaling more dangerous servants to come to its aid.