Pythid

Description
Pythids are black, squid like terrestrial creatures that live deep in the caves of Atherton, particularly the crevices which line the walls. They have long, rubbery tentacles, which let them move quickly. Pythids are sentient, but not believed to be sapient. Despite showing some carnivorous tendencies, it is unknown what their primary source of nutrition is due to the lack of prey species inside Atherton.

Appearance in books
When Samuel and Isabel are running from the Centurion, they are captured by some of the Pythids, which drag them into a crevice. While Samuel and Isabel trying to escape, the Centurion catches up with them and kills the pythids. The Centurion shows that he is friendly, and eats some of the Pythids. He also roasts some of the Pythids for the kids to eat, which are described as "Chewy".