Shoot it in the gut. Monsters hate that!
From Create Your Own Story
You shoot it rapidly in the gut, forcing it to walk backwards into the hearth, where the fire consumes it. The other folks unlock the doors and run back down the stairs to join you. The guy with the crown gives you a big hug and introduces himself as King Hrothgar of Castle Harlot.
"Why do you call it that?" you ask.
"Well, that's easy. I sell pleasure robots," the king says. You nod because that makes perfect sense. "Would you like to sample my wares?" he offers, "they make great omelets."
"That's ok," you reply, heading for the door.
"Wait!" says Hrothgar, "The beast you killed. It has an angry mother who might come after us. We won't truly be free unless you kill that."
"Does the beast have a father too?" you ask.
"What?" says Hrothgar, taken aback, "Hell, no. That's stupid. Why would a monster have a father? Anyway, can you go kill the mommy for me? She lives up at that house on the hill. Don't be fooled by the wheelchair. She's actually a hybrid abomination from a strange dimension of moving shadows and slithering tentacled eyes."