"Ah,” says a voice, “One could not write it better.” And as the voice says it, its bearer rotates around the carousel and into view.

This is not a man—not in the traditional sense. He wears a theatrical cloak, and a large pompous hat, decked with a red and green feather. But the clothes betray a body that is only facsimile. His arms and legs are seemingly made of an alabaster porcelain inlaid with intricate runes painted calligraphically in a celadon paint. Between these limbs, you see sinews of golden string strung as tendon, constantly moving and threading, as if passing through a complex loom. His long legs, which are arced like a rabbit’s, bring him to over seven feet tall, and his long fingers end in fine-needled points.

Zezrier is the master of Gardenwall's Sunken Theatre, one of the eight "On the Lyrical Ballads of Greater Powers", the (assumed) father of Trelyn, and an antagonistic figure to the party.

The party first encountered him in the Carousel Room after descending into the theatre.

A monstrous construct, it is discovered that he is responsible for creating the various puppets - as well as, seemingly, living replicants.

The party infiltrated his theatre and fought through until they encountered him in the Grand Stage. Zezrier presented the party with doppelganger Kellams, mocked them for their ignorance, and animated a large constructed dragon.

In the ensuing fight, the party was wounded, but ultimately slew Zezrier, after which he careened into a deep pit.

Curse these confounderies, and again I say let them be cursed.

For in all the eons of study could I not understand these wires that bind wind and flesh.
For as perfect as the vessels I create may be, they will still not bear Trelyn’s true soul.. It is one thing for a glass flower to mimic a petal; another for it to bear true water..

No matter. I shall play the role as I must, as all must, and some day soon the rest will say, “Well played.” And they will applaud for me, and they shall bond for me this rift of life and death. 

And to hear her clap with hands made of flesh shall be the greatest applause.

-Zezrier, in a journal entry