Karnak feeding on a fish
The karnak dwells throughout Haven, but mostly by the Shipwreck and the Lake. Known for its high-pitched screeching and "giggling" sound, the karnak is mainly a scavenger and eats whatever is leftover, including dead animals or fruit. Otherwise, it dives into the water and catches fish.
Its only natural predator (besides Achenar) is the cerpatee. After Achenar killed the local cerpatee population, they began to rapidly reproduce and became bolder while searching for food by hunting in packs. Achenar found them to be a nuisance because they stole his supplies, and built several contraptions, such as the shipwreck elevator, the gate, and the tube lock, as well as several traps in order to keep them away. While these contraptions likely served as a somewhat effective deterrent to the lake karnaks, who seem to be incapable of sustained flight like their coastal brothers, the coastal karnaks would have been able to fly over these obstacles.
While it has been suggested by the Prima Strategy Guide that Achenar was so mentally unstable that he was unable to realize the karnaks' ability to fly when he built his security measures, RAWA has noted that much of what appears in the sidebars of the Revelation Strategy Guide should be considered apocryphal. Given Achenar's otherwise prescient insights into the behavior and characteristics of the creatures he lived with on Haven, it seems unlikely that he would have failed to grasp such a basic capability in one of his prey. It is more likely that Achenar initially built his contraptions to keep out the short-ranged lake karnaks, and over time the coastal karnaks simply began to expand into the same territory, rendering his blockades largely ineffective.