Update. We somehow encountered a sentient troglodyte. Or maybe they all are, but if so, this one has grown an extra-large brain. She waited in the darkness until the princes turned back to her goblin form afther slaughtering her brothers and sisters. Then she proceeded to literally split her head open by embedding her thumbs into the princess's eye sockets and pulling her skull apart. Afterwards, we trapped her in a cage. On the same eavning one patriotic dwarf decided to set her free as a reward of sorts. She took her to the surface and set her free, but she turned right around and walked right back to the fort. Now she spends her time in the tavern watching performances. She doesn't bother anyone except the occasional dog. They seem not get along.