The Crawler, as it is labeled by the biologist of the 12th expedition, is a mysterious entity living within Area X.
The Crawler appears to be an integral component of the "mechanism" that is at work throughout Area X. It inhabits the tower, and appears to constantly, albeit slowly, move up and down the spiral staircase of the structure. As it does so, it writes upon the descending left-hand wall of the tower, inscribing English words in a cursive script. These words are composed of a colony of fungus-like organism that resembles green moss.
Although the content of the Crawler's "message" has been recorded by multiple expeditions, its meaning remains largely obscure. The most complete recorded segment, beginning at the top of the spiral staircase, runs as follows:
"Where lies the strangling fruit that came from the hand of the sinner I shall bring forth the seeds of the dead to share with the worms that gather in the darkness and surround the world with the power of their lives while from the dim-lit halls of other places forms that could never be writhe for the impatience of the few who have never seen or been seen. In the black water with the sun shining at midnight, those fruit shall come ripe and in the darkness of that which is golden shall split open to reveal the revelation of the fatal softness in the earth. The shadows of the abyss are like the petals of a monstrous flower that shall blossom within the skull and expand the mind beyond what any man can bear..."
Other known fragments include:
"There shall be a fire that knows your name, and in the presence of the strangling fruit, its dark flame shall acquire every part of you."