The Eighth Doctor encountered the Zygons in the spin-off novel "The Bodysnatchers" by Mark Morris, which also named the now-destroyed Zygon homeworld as Zygor. The novel also revealed that Zygor had been destroyed as a result of an attack by an arachnid alien race from Tau Ceti, the Xaranti. The Doctor, his companion Sam Jones, and the Fourth Doctor's old acquaintance Professor Litefoot are able to stop the Zygons by poisoning the milk supply (although the Doctor had intended to merely drug them and miscalculated the dose), the Doctor taking the survivors to another planet.