The purple-green space devourer is a carnivorous plant that can move, eats people and survives in vacuum without needing oxygen. It reproduces on its own, without a partner, and likes to be near technology. It leaves plant fibres, slime and purple leaves behind it, bites limbs and faces away, and has a distinctive radiation signature.

The fleet first met it aboard a derelict in the Ragnhil debris field, whose crew seemed to have been studying it before it got out: the captain was torn apart in his locked cabin, the medical officer dead by his own hand, and three of the plants were on the bridge. The salvage team took the ship's data and the plants' radiation signature and were decontaminated when they got back, and the ship, in a decaying orbit, was due to be fired on. Another had been kept in a containment lab aboard the Cradle. Jahori brought samples home for the Hercules bioresearch lab, and the devourer is a large part of why people argued that risky research belongs on its own ship.

On a crashed ship on an ice moon, A Blip in the Dark found what a mature one does to a vessel: thick vines weaving through the wires, circuits and machinery from somewhere near the reactor, cat-sized bulbs nested in the terminals, flowers that bite, and vines that pierced the hull and grabbed the crew. A bioscan of the charred vines matched the devourer's DNA, from a mature specimen. Fire worked.