Shade
Monster Junkie
I do have one question. Why does its acid not affect stone? Its description says it eats minerals and creatures from the elemental plane of Earth, surely it stomach acids can digest them!
That's a holdover from the ooze I copied it from, and most certainly needs to go! Good catch.
I was also wondering whether it could have the Earth or Extraplanar subtypes since it eats Earth creatures. A glitterworm's not an Outsider or Elemental though, so I'd deduce it's unlikely.
It doesn't appear to be from another plane, so not Extraplanar. An argument could be made for Earth, though, as some non-outsider/elementals have it, like stone giants and blue dragons.