You have wandered into the lair of the evil monster Kuromaru. It is just supposed to be a floating rubber ball with a single eye, however it is known to corrupt and break heroes into following it, or feeding it their life force. It's lair is entirely rubber and goo, and your feet squelch against the floor until you come across it in a grand room filled with defeated heroes being drained.

"Ah! A new face! What brings you here to the lair of the great Kuromaru? Are you a hero? An adventurer?"