It Was A Dark And Stormy Night...

You look for the freshest tunnel, the one with the loamiest and dampest soil. You find one and follow it as fresh grit and partially sliced worms drop onto the path ahead. On the way, you find a a silky sack with an item inside - you make a mental note to inspect it later, taking it with you. Eventually you come into an opening where something writhes in the back of a large room.

Before you writhes a large brown worm with markings resembling carved rock. This eyeless creature shrieks at you, revealing a mouth with too many sharp points. For some reason, you immediately understand it's name: Thomas. This must be the source of the vibration! That means it must be dealt with. Your guide nods to you, ready to follow your lead.

What do you do?