Titan Needle

Titan Needles are giant worms around 50 feet long and 5 feet across at the widest, that look a lot like a needle and thread- their front 40% is shaped like a sewing needle (without the eye), with the remaining 60% hanging behind like a massive thin thread (covered with small spikes). Titan needles are able to dive through the Earth at fairly high speeds and magically move the earth around them as they do so (leaving behind long tunnels). Titan needles are unique in that they not only can touch incorporeal things, but slowly digest any incorporeal thing that touches them. They gain quite a lot of sustenance from eating cave ghosts this way. To help them find these illusive ghosts, they have very nice hearing and can recognize Deep Songs quite well. They also have big-cat levels of predatory intelligence, and enough articulation and foreplanning to weave their bodies through the earth to trap their prey.
They do not naturally hunt corporeal creatures and they don't much care about corporeal critters at all unless said critters are attacking them. That said, they do get territorial over nests if they have young: Titan needles live for 200 years and breed very rarely in large nests- they really have to rely on running into others of their kind to find a mate. This makes nests rare, but dangerous. When a titan needle gets defensive, it can either dive its beak into a target at high speeds (if it is being attacked, this is common as it lets the needle run away afterwards) or open its piercing needle-beak like an octopus beak to bring out 3 long tentacles tipped with venomous stingers (this option is for when it can't run away, such as when its defending a nest). Distribution is the same as cave ghosts, but in much smaller numbers
they can eat ice! and also I imagine that the titan needles do cause a bit of a mess- while their tunnels may not be massive in diameter, they could certainly be a nuisance or cause a disruption just as easily as their tunnels could form a passage