By the hand of the Fifth and Final priest of the Astral Seas
The Library, more commonly known as the Wanderers' Library, is the finest source of knowledge in all the worlds. No empire or civilization has ever come close to rivaling what the Library has to offer, even that of those of the forgotten names, who know what IS and what IS NOT.
It is said that the vaults of Alagadda hold several texts of forbidden knowledge that were stolen from the Library, but I shudder to think of what price the Hanged King and his Masked Lords would demand for a mere taste.
Yet despite the wonders that lie before me, such as the texts on the demon foxes and a tome on the practices of the Howling Dark, I find myself with little to peruse on my chosen subject: that of the Serpent itself.
It sounds strange at first glance, perhaps even laughable. Even those with the newest cards would tell you that the Library was built upon the Serpent's back, and it is by his devotion that this place exists. The group of misfits known as the Serpent's Hand style themselves after it, with many worshiping it as a trickster god (some believe this is how they retain their library cards, but there is little proof of this).
A closer glance at the litany of volumes on the subject reveal many take their ideas from earlier works. One Allison Chao (a name that seems to repeat itself throughout the shelves, curiously enough) states in her book, Our Prometheus;

Gossip would have you believe that the Library is located on the Serpent's back. This is a metaphor, taken as fact. The Library was built upon the back of the Serpent, who labored to create this sanctuary of knowledge. The Serpent does not even exist as a true being, it is a Platonic ideal of knowledge at any cost

If true, it would be of great value to my works. But how did she arrive at this conclusion? Later in her text, Chao cites a series of scrolls by Sera of the Infinite Chaos, a Daevite priest of the King Adorned in Red, on the nature of divinity and true faith. The relevant passage, compiled here, details his thoughts on the Serpent.

The law of howling and the law of blood are the chains that bind him. Like the Serpent, who pursues his secrets eternally

A lazy citation by itself, but she proves her credentials. Ms. Chao cites three additional well-respected authors, who provide relevant documents and thaumalogical workings to lend credence to their assertions. All seem to agree that the Serpent is not a true being, but an aspect of knowledge to have faith in.
A closer look at these sources reveal a troubling trait. An alarming number of her sources, and her sources sources' appear to share a small group of common references. Established facts devolve into conclusions, which devolve into assumptions, which devolve into hypotheses. Ultimately, this particular strand of knowledge can be traced to the collection of writings of Xilaskar, last of the Yeren.

If we examine the Serpent from the perspective of a being composed of knowledge, with an eternal hunger that can never be satisfied

A theoretical position that had been twisted into hearsay and tempered into a fact. It is curious that the Librarians, many of themselves paying a penance for introducing falsehoods to the Library, would overlook something like this.
I may have dismissed this as a simple case of non-omniscience, had a Librarian not come up to me and inquired into the nature of the research I had been conducting. It was unable to assist me, but pointed towards me a distant corner of the Library, a hundred leagues south of the main desk, that could prove useful. Suspicious, yes, but it was something concrete.
My teleportation techniques in extradimensional spaces are woefully out of practice, so I endured the long and arduous journey. Each day of travel, I seemed to be heading into a quieter and less trodden part of the Library. The Library was ancient beyond measure, but it seemed the parts that I was travelling to were older than that, if it was even possible. Carefully constructed wooden floors turned rougher and rougher, until I was walking on dirt packed between interwoven branches.
That is where I found a most curious surprise, in a room that had been forgotten by time. A single bookshelf was all that was present within, with six books on it shelf.
I opened the first one and began reading. It was the journal of, strangely enough, Allison Chao.

Ananteshesha. Nahash. Satan. To those who know where to listen, these are the names repeated in the same breath as the mysterious god of the Wanderer's Library. But behind those, there are only rumors and conjecture.

It seemed that this Allison Chao (who must be different from my previous contact, I'm sure of it) was a wanderer seeking knowledge of the Serpent, and ended up in this curious room much like myself. I grabbed the next book on the shelf, this by a Lord Theodore Blackwood, and skipped ahead to the end.

While my inquiries about the Serpent have resulted in frustratingly little, it has led me to this odd little room, with Ms. Chao's ruminations on the serpent to add to my collection. Perhaps whoever finds this collection of musings can solve this elusive riddle.

The next four were more of the same. Each author had been an explorer searching for information on the serpent, only to arrive at the same room as I had when they fell short of that goal. Each appeared to have incorporated the previous one's work, building to a bigger, yet incomplete part of the mystery.
I must've been there for hours, adding every little scrap of their work into my own, crossing off avenues that they had already explored and debunking theories they had tentatively proposed. When I beheld the fruit of my labors, it still fell woefully short of a definite answer on the nature of the Serpent.
But hopefully, whoever came after me would have something to pass on.
I paused at that thought. Was this all by design? The web of misinformation surrounding the Serpent, the books with their woefully wrong conclusions, it all seemed to have led me to this room, for passing on my knowledge to the next generation of seekers.
If so, who was the architect of this scheme? The Librarians? Or was it the hand of the Serpent, placing a test to see who truly deserved to know the truth? Or did it never exist in the first place, and instead was tentatively forging its own history?
As I sit here now, scribbling the last remnants into my journal for whoever stumbles onto this hidden corner of lore, I leave you these words.
Good hunting.