They appear to be very dark, overly large worms - perhaps a handspan in length and half as thick as a finger. That and their matt, dull skin marks them as something other than a typical earthworm.
What do you mean, the little wriggly ones you throw at fish or the big rock ones that squish people?
Six months of hunting, six months of research and paying coin to scholars and sages, and now that we have the legendary wand of Geohadris the Stone King, it only summons stupid boulderkin? I am outraged beyond imagination!
Mapmaker's bane, a few of these can ruin a decade of cartography!
King Addas loves charades, and has a troupe of mimes in his harem. To ensure that they can never cheat he has had their tongues cut out, which is why they always look so miserable and never open their mouths (the stump of a tongue is not a pleasant sight).