Urnsor'is

The Urnsor'is were a species of non-sentient parasitic spiders first documented in the Myyydril Caverns on Kashyyyk, though it was unknown if they were native to the planet. The Mother Queen was known to be the source of the infestation within the caverns. They first came in contact with the Wookiee population when Wookiees of the Myyydril tribe came upon a single egg. This hatchling ultimately produced more offspring, which latched onto the skulls of Wookiees and fed on them. To ascend to adult status in their community, the Wookiees of the Myyydril tribe were required to kill an Urnsor'is, a quest that often failed in the face of the creatures' killing prowess. Whenever a Urnsor'is was killed, the purple sacks on its back would burst and cover the unfortunate killer with voracious hatchlings, which would consume them in a matter of seconds.

The name "Urnsor'is" meant "mind pod" in Shyriiwook. Some of the most feared Urnsor'is infected their victims with a flesh-eating virus called Poltur, for which there was no known cure.