Tsuchinoko (Mongolian Death Worm)

This creature dwarfs an ordinary Mongolian Death Worm, which Okarun notes typically runs only one and a half to two meters long. Its serpentine body bears a spotted pattern, and its mouth gapes open ringed with tentacles and lined by several rows of teeth.

Back in the feudal era the worm made its home inside the village volcano, stirring eruptions whenever hunger struck. To shield the settlement from the magma, the Kito Family began offering one village child to the worm at a time, a grim ritual they sustained for two centuries. One of those sacrifices gave rise to the Evil Eye. The Tsuchinoko also built a nest and laid countless eggs; long after its death, Naki would discover the clutch and hatch one to produce a new Great Serpent.

The worm's most fearsome weapon is a psychic influence that drives those nearby to take their own lives, snaring Momo and Okarun during the fight beneath the sacrificial house. When the Enjoji parents moved into that house, the same power left them hospitalized. It can also unleash electric shocks, spew binding phlegm, and release poisonous spores to choke out enemies who linger in its lair. Even decapitation barely slows it, since it regenerates from grievous wounds. Its one true weakness is water and sunlight: drenched ground keeps it from staying underground, and once exposed to daylight it begins drying out. Momo finally killed it by hurling a fire truck to demolish its cover, and afterward the trapped Kito Family were vomited up alive from its corpse, which was then repurposed as a hose to cool the volcano's magma.