Hydra, who is named Inevitability, is a great and coiling beast, who grows two heads for every one that is cut free of her. She is often found in the Walking Fields, but makes no permanent nest there, roaming instead as she pleases.

While traveling the Fields to visit distant family, the rat Sibyl happened upon a spring. She was thirsty, for the trip was far and the days were long and hot, and so she descended down the hillside that sheltered the spring and pricked herself on some brambles on the way. As she drank the clear waters, she found herself filled with a coldness, a disinterest in the family she came to visit. 'What matter are they?', she thought to herself, 'that I should trouble myself so for them?'

Sibyl set out again, increasingly listless as the poison crept through her body and hardened her heart to the world, until she met a cat on the road.
"Little rat", the cat called out, "why do you not fear me?"
Sibyl considered their question. "Before, I would have said 'because I am a brave rat of the Far Roofs, who knows no fear', but today, it is only that I know I will die, and if it be by your claws, it is no different than any other."
The cat shook its head. "In the woods you met a monster, and it has poisoned your flesh and mind. Give me your name, and that of your family, dear rat. I will share with them news of your passing and the lore of the animals of the Fields, that they may add it to their Book."

In this manner, Sibyl's family learned the secrets of Hydra.

Hydra is named Inevitability, the certainty that you will one day die

The heralds of Hydra are land turned barren, growing only thorns; the coils of a vast beast twisting in shadows; teeth of metal, buried in the ground; a physician who consorts with wicked things

The weapons of Hydra are wicked poisons; piercing brambles; shards of broken metal; and disregard for the lives it hurts

Hydra kills by hardening your heart; by drowning you in poison; through ten thousand cuts; by bleeding you with briars; and by tearing you apart in her maws

Hydra is drawn to righteous heroes; struggles against the inevitable; poisons; wielders of power over life and death; innocent hearts and hearts jaded by cynicism

You may turn Hydra aside by disregarding the value of others' lives; by accepting your death by her hand; by drinking deep her poison; by treating her with the deference she believes she deserves

You may kill Hydra by burning her every last head and body until nothing remains but ash

Hydra is reborn when briars take root in a hardened heart; a field is sown with shards of metal and broken blades; a king rules unjustly and cannot hear the plight of their people

[Beneath Hydra's entry, a line is hand-written in: "Hydra may be bound with a desperate gamble, a sacred vow, or with love born of struggle"]