Millie/History

Past
Not much is known about Millie's childhood, except that she was raised in a large family in the Wrath Ring by Lin and Joe.

Lin and Joe would bring Millie and her siblings to Loo Loo Land when they had the money, and the last time she went prior to the series was when she was still a tot.

Millie participated an unknown amount of times in the Harvest Moon Festival Pain Games, where she killed other contestants and wracked up a neighborhood head count.

In the previous Harvest Moon Festival Pain Games prior to the series, Millie caused nine of the fifteen funerals from the event and was subsequently banned from participating in future.

At unknown points before the start of the series, Millie left the Wrath Ring, briefly dated Chazwick Thurman, met and married Moxxie, and joined I.M.P.

Helluva Boss pilot
NOTE: The events depicted within the episode are confirmed to be not canon to the main Hazbin Hotel franchise by the creators. Millie is in the I.M.P Headquarters meeting room discussing how to improve the company. The group begins to argue and Eddie belittles the team, but after learning Eddie was indeed the target they take great delight in killing him.

"Murder Family"
At I.M.P Headquarters Millie watches as Moxxie aims his crossbow at a picture of an "innocent" family held by Loona, but Moxxie worries about having to kill a human family, Millie replies that is not their say on whether or not someone is innocent and their job is to kill whoever they're paid to kill. When Blitzo enters the room to introduce their client, Moxxie is startled and shoots a bullet that ricochets around the room, knocking over a tank of eels and setting the building on fire.

When they reach the targets house Blitzo is about to shoot the target until Moxxie purposely makes him miss because she had her family with her. Blitzo scolds Moxxie but after getting shot in the arm he tells everyone to flees. Millie escape to the docks, where she is gets in a fight with Ralphie and loses.

Millie wakes tied to a stake with Blitzo, Martha tries to burn them but when fire had no effect on them, she tried to shoot them, only to be killed by Moxxie. Back in hell, the gang celebrate a successful job.

"Loo Loo Land"
Millie was overjoyed that she and along with the rest of I.M.P, got to Loo Loo Land as hired guards to protect Stolas and Octavia.

Millie takes Moxxie to ride on "The Lawsuit" roller-coaster, which makes him throw up afterwards, and the pair end up at a shooting gallery carnival game. Moxxie enters to win Millie a "Thing?" and shoots a bullseye but the target doesn't go down, and the operator goads him into continuing to buy further games.

Millie attempts to shoot the target but despite missing the target goes down, leading Moxxie to call out the operator, but is pushed aside so the operator could flirt with Millie. Suddenly, Blitzo falls through the roof of the shooting gallery and Moxxie takes a "Thing?" as he and his wife run off to guard Stolas.

Later, they're rides upon a dragon that eats the Robo Fizz attacking Blitzo. Then he, Blitzo, and Millie are sent flying outside Loo Loo Land, commenting that Blitzo ruined another good thing before passing out, while Millie is dragged away by quieves.