An aberrant visitor from the Far Realm now lives under the well. The creature was summoned by an accomplished spellcaster who is now a thrall to it. The creature has lived under the well for a few years. The people in the town above fear and respect it so they feed it livestock and farm produce.
The creature has grown in size and aggressiveness over the past few weeks. A person is missing and the townsfolk believe it was the monster from the well. Will there be anyone brave enough to follow the tentacles down the well and put an end to this?