Here is a sneak preview of the N’Kai Worm who will debut next month in The Big Sleep, Act 4: Lullaby.
Deep in the inky depths of N’kai, some of Tsathoggua’s formless spawn have spontaneously merged and taken on a worm-like form with mouths at both ends. These twenty-foot-long columns of ichorous protoplasm can slither like snakes, undulate like caterpillars, grow hundreds of lateral tendrils to walk like centipedes, and can even swim or burrow.

While at rest, they can disperse their form across a wide area, appearing as a puddle or an oil slick, but reforming in an instant to attack. This wormlike mass of twisting black ooze wriggles and undulates as it rears to attack, opening a shapeless maw lined with jagged, irregular teeth.