Thorn Spawn are the living victims, and dead thralls, of the Puppeteer Thorn plant. Living in agony, or dead vassals, the kindest thing to do to one is ensure they no longer move. They are found around the Thorn Temple, in the highlands of Thistleland.

Thorn Spawn are infected by the Puppeteer Thorn plant via individual thorns puncturing the skin. These thorns will then grow into a new plant if not soon removed, which burrows into the host and spreads throughout the victim over several hours. While growing, the vines within will sprout their own thorns, slicing the insides of the victim. Over time the Puppeteer Thorn will control the movements of the victim with increasing efficiency using the pain of the thorns cutting the host internally.

To infect a person with a Puppeteer Thorn, either a infected host will be forced to attempt to bite the intended victim, or a large Puppeteer Thorn vine will attempt to swipe or grapple the victim. Both these attempts are aimed at stabbing the victim with one or more of the claw-sized thorns, which will easily detach from the plant once inside flesh. Once a thorn enters the flesh, it will push inwards a way, and hatch: In reality the thorns are the Puppeteer Thorns versions of seeds. These new plants will then start to push into the body at all angles rapidly, feeding on the blood and nutrients of the new victim as a fuel source.

While at first hidden from view, later stages of Puppeteer Thorn control will become more obvious with clusters of thorn vines in the maw, the many thorns appearing as if the victim has rows upon rows of pointed teeth, as well as the occasional thorn vine protruding from cuts in the body.

Due to the destructive nature of the Puppeteer Thorn, the victim will eventually expire from the injuries constantly sustained from attempted resistance to the Puppeteer Thorn and it's controlling attempts. However, by this point the Puppeteer Thorn will be at the stage where it will be able to infest the bone structure and operate the body on it's own, crating a shambling monster that slowly decays even as it lumbers forward. Eventually, however, this form will collapse from rot, forming a new potential colony for the Puppeteer Thorn to grow from while using the corpse as a nutrition source.

As with the Puppeteer Thorn, Thorn Spawn can only infect warm bloodied animals, and are highly venerable to enchanted Bonewood weapons. When not splayed by these weapons however, a victim can expect to suffer for months as a Thorn Spawn host, and post death will be mobile as a dead Thorn Spawn for potentially years.

Due to their resistance to Thorn Spawn, the local villages around the Thorn Temple are populated mainly by marsupials, primarily opossums, kangaroos and wallabies. These hardy people have successfully kept Thorn Spawn from spreading outside the area of the Thorn Temple, though due to the dangers within the Thorn Temple itself from both Puppeteer Thorns and a large number of Thorn Spawn such people do not venture close.

Those who have been bitten by a Thorn Spawn and successfully pulled the Puppeteer Thorns from their bodies before being infested are advised to use antibiotic and/or antiseptics, due to the risk of infection from corpse bites.