The Death Worm (in-game name Kalmamato) is a large ghostly worm native to the Temple of the Art.
Behaviour & Combat
Kalmamato moves around in the same way as the regular Mato, with the exception that it doesn't eat any terrain and instead just passes right through it. This makes it harder to detect its presence before it strikes, as it leaves no tunnels to indicate that it's nearby. It can take a sizeable amount of punishment before dying, and unlike Jättimato it doesn't drop anything when killed.
Since it doesn't eat through terrain it's possible to find the worm stuck in an infinite loop of trying to burrow upward, not having ground to burrow through, and falling back down only to try again. It can sometimes manage to turn itself around, but in many cases this makes killing it quite easy.
As with some other ghostly enemies like Houre, Kalmamato seems to be able to detect the player even if they are invisible.
Kalmamato seems to be hostile towards the traps frequently encountered in the Temple of the Art, yet is unable to actually damage them, thus it ends up stuck in place until the trap is destroyed.