Kozilek is the truth behind the merfolk myth of the trickster god Cosi, a reality-slicing abomination of relentless insanity. Kozilek represents themes of deception, puzzles, lies, mind domination, transformation, and experimentation. Sages call Kozilek the confusion of panic, the trap of enigmas, and the harrower of thought.
Kozilek is known for affecting the environment around him, warping the laws of physics. When Kozilek is around, things don't work the way they normally do.
Death by death, Kozilek's lineage spread. (Spawning Breath)
Left masterless by Kozilek, it wandered the wilds, raving in its ceaseless hunger. (Escaped Null)
You will scream out your innermost secrets just to make it stop. (Inquisition of Kozilek)
It's difficult to outwit something that doesn't speak, strategize, or even think. (Kozilek's Predator)
The lineage that spawned from Kozilek, Butcher of Truth shares a set of frightening physical characteristics. The most salient is the knobs or bladelike plates of some glossy black material jutting from, or hovering near, their bodies. These sharp projections tear effortlessly through physical substances, including armor and living tissue; yet the Kozilek lineage creatures seem not to use them intentionally as weapons. The projections may be defensive growths, organs of communication, or simply decorative features of the species; the extreme danger of the Eldrazi leaves little time for meticulous study.
Another feature of the Kozilek lineage is their often multi-legged, animalistic, or insectoid body plans. Some Kozilek-lineage creatures have bifurcated arms like the Ulamog lineage, but Kozilek limbs tend to branch with stranger, more awkward angles. The forked elbow structure is curious; it could indicate an adaptation used for climbing through caves and subterranean ruin passages, although it appears on some greater Eldrazi that are many stories tall. Although creatures of the Kozilek lineage often have animalistic skeletal structures, they always have their own horrible divergences from those natural forms, leaving them completely alien.
Creatures of the Kozilek lineage often have eyes or eyelike protuberances in odd places, such as at limb joints or scattered seemingly randomly along the creatures' flanks. The appearance of such normal-seeming mammalian sensory organs on creatures such as the Eldrazi is jarring to say the least. Some have speculated that the eyes were grown as an attempt to mimic the life of Zendikar, the better to hunt such prey, but that the imitation failed or was halted, and only the eyes and vaguely bestial body shapes remain. The eyes do seem occasionally to aim and focus, but usually only at empty space—or perhaps they focus only on ineffable things that exist beyond the normal spectrum of visual light.