It is first used by Mingella and Blobbelda to reach Spiral Mountain, sealing off Grunty's Lair in the process. After freeing Gruntilda and allowing her to take her revenge on Banjo, the sisters get back into the Hag 1, let a bunch of monsters out of it to infest the Mountain, and create a large hole in the wall of Spiral Mountain, escaping back to their hideout. Their escape route takes them through Jinjo Village, causing them to destroy the the house of the Gray Jinjo. There route also leaves a clear trail to their hideout, Cauldron Keep.
When Banjo and Kazooie reach the roof of Cauldron Keep, they find Gruntilda inside the Hag 1. She will attack them violently with it, using it's various abilities (including poisoning the air surrounding the machine) but eventually the machine is destroyed when Kazooie shoots a Clockwork Kazooie Egg into the main engine chamber. It has not been seen since, and presumably the machine was destroyed beyond repair.