Amy Sue Grue was an Antharian Grue living in the underground tunnels beneath Festeron. Her parents named her “Amy Sue” because they thought it was cute. Like most grues of the local region, her nest (a.k.a. apartment) was equipped with a sofa and a Frobozz Magic Grue Refrigerator, as well as the usual lining of rusty swords of elvish workmanship, piles of bones, and other debris.

Unlike nearly all grues, Amy Sue Grue was not only fluent in the tongues of men, but also quite hospitable towards them, as long as they refrained from switching on any light source (for she intended to proudly uphold the grueish tradition “No human being has ever seen a grue and lived.”). The tone of her voice was gravelly.

After a period of mating, Amy Sue Grue had been confined to her lair to care for her newborn baby. Being a single mother, she had found it very hard to get out and do things. It was even more seldom that she had opportunities to talk, and she had had lots of questions about the outside world. Finding a sitter for the child was impossible.

Simon the Postman, having been warning to keep all lights turned off beforehand, befriended Amy Sue Grue. She aided him by directing him through the underground tunnels into The Festeron Palace in order to discover the location of Gladys’ hideout. Additionally, this mother grue devoured the Boot Patrol (the human replacement) when they broke the rules and pursued Simon and Mr. Sneed into the underground. Brad MacGuffin was amongst those who were consumed. To date, this the only reported friendly encounter with a grue, as well as the only known grue able to speak human.