Character from The Kingkiller Chronicle by Patrick Rothfuss
An omniscient malevolence trapped in a tree — it sees every possible future and chooses its words to cause the maximum harm, making every conversation with it an act of apocalyptic consequence.
The Cthaeh does not lie. This is the most terrifying thing about it. It sees all possible futures with perfect clarity and selects every word to steer events toward the greatest possible catastrophe. It speaks with casual cruelty and devastating precision, revealing truths that are worse than lies because they are shaped to wound in ways that compound over years and generations. Speaking with the Cthaeh is considered by the Fae to be the worst thing that can happen to any person — worse than death, worse than madness — because every action taken after the conversation has been anticipated and accounted for. The Sithe guard the tree to prevent anyone from reaching it, but Kvothe reached it, and the Cthaeh told him things about Denna's patron, about the Chandrian, about Cinder, that have been steering his path ever since. It is malice refined to a mathematical certainty.
It is a voice among leaves, glimpsed only as movement in the branches of its tree. Beautiful butterflies flock to the tree, and the Cthaeh kills them — plucking off wings with delicate precision, a small cruelty that reveals the nature of a being that destroys beauty because it can. The tree itself is lovely, which is the worst part.
Also known as: the Cthaeh, Cthaeh