"Grafenwalder's Bestiary" is a short story set in Chasm City and the Rust Belt, some time after the Melding Plague. In this story we also get to meet Dr. Trintignant, one of the main characters of the novella Diamond Dogs. The story was published as part of the collection Galactic North.
Grafenwalder is a collector of specimens of alien animals and freak human creations, having them on display in his bestiary. He is especially searching for a Denizen, one of the bio-engineered creatures from the Demarchist society on ancient Europa. Some Ultras arrange for him to get a hamadryad, a very rare animal native to the planet Sky's Edge. When they reveal another collector, Ursula Goodglass, has also got one, he bribes them to kill hers. Later, when Goodglass is showing it off, he reveals that it is in fact dead. Although he is temporarily ahead in the constant competition between animal collectors with his living hamadryad, Goodglass catches up by unveiling the living nervous system of Dr. Trintignant. She offers him the choice of killing him or letting him continue to suffer. He chooses the latter. Grafenwalder plans revenge, but is unsure what to do. An Ultra called Rifugio arrives and promises to bring him a Denizen. He provides samples of its DNA, which appear to match Grafenwalder's templates for Denizen DNA. The purchase takes place, but Grafenwalder is unable to detect any sign of intelligence in the Denizen. It is exceptionally strong, but cannot talk and cannot communicate. When Grafenwalder presents it with buttons, it only presses the one that produces food. To make matters worse, Grafenwalder's scientists reveal that it is in fact a fake. Even so, he invites Ursula to see it. She reveals that she is the Denizen, surgically altered to become human. Her real husband died long ago, and the current "husband", who has spent years in his palanquin (a device that blocks out the Melding Plague), is actually Trintignant. Grafenwalder is really a scientist who tried to stop his rival from creating the Denizens, introducing pain and suffering to the Denizens' lives, but gave himself false memories of his life after Europa fell. Ursula has disabled his security system. It is implied that Trintignant turns Grafenwalder into another of his monstrous creations.