Status Status
Race Cthonian
Location(s) Cthonian Tunnels

The Cthonian is a great burrowing worm that lives in the tunnels it created beneath Derceto Manor. It is a powerful monster and the only one who resists Ezechiel Pregzt and can not be destroyed (nevertheless, it disappears along with all the other monsters upon Pregzt's demise; whether it is destroyed, or simply departs, is unclear). The creature has long tentacles it uses to pull its prey into its mouth.


The Cthonian acts as an obstacle in the tunnels, and as a mean to destroy obstructing boulders.


There is no way to defeat the Cthonian, and any attack from it will kill Edward Carnby or Emily Hartwood automatically (a quick glance at the status screen after being hit by the Chthonian but before the game over message will usually reveal the player's health to read in the negative teens). Thus, it must be evaded at all cost and lured into moving to destroy the boulder blocking the path, but the player must not stay in place or the creature shall devour them.

It attacks with its long tentacles. Before attacking it bunches up its body, telegraphing its movement. When lured to the boulder, the player must wait for the Cthonian to pass.

By moving fairly rapidly between the Chthonian Tunnels and the Underground Piers, the player can trigger a glitch which shows the Chthonian in the distance, either stretched out across the screen or at normal proportions yet overlapping the 2D background (see the video here[1]). The glitch is purely visual and does not affect gameplay.


  • In Greek mythology, 'Chthonian' refers to a being that inhabits the underworld; they are considered to be the dark, shadowy counterparts of the Olympians.
  • In the Cthulu Mythos, Chthonians are described as immense squids, with elongated worm-like bodies coated with slime. Despite their squid-like appearance, chthonians are land-dwellers and are even harmed by water. Chthonians are powerful burrowers, live for more than a thousand years, and are protective of their young. It is said that a chanting sound accompanies every chthonian, and that by such they can be detected while underground and unseen.
  • While part of the Cthulhu Mythos, Chthonians are not explicitly Lovecraftian in origin. Rather, they first appear decades after H.P. Lovecraft's works, and are described in detail in the story The Burrowers Beneath.
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