Millie

"It doesn't. It matters how I feel about myself. And, for once, I feel like... like I'm important. Like I'm someone to be proud of... And I had hoped that my husband would be there to support me half as much as I've supported him this week!"

- Millie, reprimanding Moxxie

Mildred "Millie" Knolastname is an assassin at I.M.P, Moxxie's wife and one of the main protagonists of Helluva Boss.

She is the exciteful powerhouse of the I.M.P gang who always fights alongside Moxxie.

Appearance
Millie is a short imp whose red skin has white markings on her forearms and on her devilish tail. She has a pair of thin white-striped black horns and short messy, bob cut-styled charcoal hair with bangs that cover half of her right horn. Her eyes have yellow sclera and long thick black eyelashes extending the sides, and with a small beauty mark under her right eye.

Millie's head is noticeably more human-like than most imps (although still without a nose) since she has proportions that are noticeably rounder, and front teeth which possesses a gap that are flatter than the sharp, conical teeth most demons have. She also has a black heart tattooed on her left shoulder, and makeup which consists of shimmering-dark red eyeshadow, and black lipstick on her lips.

Millie's attire is all-black with a little yellow; she wears a black choker around her neck, a cold-shoulder black crop-top with the straps being held by two golden-yellow buttons, black fingerless gloves, black torn denim-pants and black toeless footwear, which exposes her hoof-like toes.

Pilot
In the pilot her appearance was nearly the same, only her skin was paler-colored and she had a white patch in her hair.

Personality
Millie is a very lively and cheerful individual. Often with a smile on her face and rarely standing still, she is a clear extrovert and is not afraid to speak her mind. This is regardless to whether it's expressing her excitement or flipping off a co-worker.

As the bruiser for I.M.P, she is shown to enjoy her job. Her meek exterior appearance belies a tough and very violent skillset. This is highlighted during a conversation Millie once had with her mother and sister. According to Moxxie, she is aggressive in "the sack" as well as her job.

In "Murder Family", she appeared to be very unsympathetic about killing a possibly innocent target, only caring if it was what their client wants, showcasing her dedication to her work, and her ruthlessness.

Despite this, she cares very much about her husband and her family. She and Moxxie absolutely adore each other, acting very affectionate and protective of one another.

She has a childlike fondness of Loo Loo Land, triggered by familial memories of going there as a child, and gets easily excited by all the merchandise.

Millie will become vicious and violent whenever someone harms Moxxie, to the point of going feral. Her violent streaks can often result in her getting carried away to the point of mindlessly attacking a perceived target, allowing her rage to override common sense, this is evidenced by her mother’s scolding her for allowing herself to be overcome with rage when she fought Striker. These rage states may leave Millie vulnerable to a more skilled opponent, as showcased by Striker incapacitating Millie in spite of him being ambushed by Millie.

Furthermore, she is also shown to be somewhat defensive of her work, expressing annoyance whenever anyone implies that freelance work doesn't pay well.

In "Unhappy Campers" it is revealed that she has some issues about how she sees herself, confessing how she sometimes does not feel appreciated enough and how she wants to be seen more than just a "killing machine", stating how it feels nice to feel important and hear the cheers and applause of people every once in a while rather than the occasional screams of agony from her victims.

Abilities

 * Earthly fire resistance - As shown in "Murder Family", Millie is completely unharmed by the effects of human world fires.

Skillset

 * Weapon proficiency - Millie is skilled at using a melee weapons, such as a giant battleaxe, to eliminate targets. Like her husband, she's also adept at using firearms, and she can also create makeshift weapons on the fly, such as when she made a Molotov cocktail to throw at the Catfish Monster.
 * Closed combat - Millie is highly adept at close combat in terms of raw strength, she is able to dismember armed human and eldritch opponents in hand-to-hand combat, being strong enough to force the jaws of a building sized monster open, or crush a human's skull with her thighs. Her actual close combat tactical skills are questionable, as she has been defeated by skilled or advantageously positioned opponents in melee combat on several occasions.
 * Swimming proficiency - She is seen to be adept at swimming as shown in "Spring Broken".
 * Volleyball-playing - Millie has proficient skills in volleyball, allowing her to make a perfect strike despite fracturing a camper's skull.
 * Banjo-playing - Millie has some experience with playing the banjo considering that she was raised in Wrath Ring in a farmlands.
 * Guitar-playing - In addition to her banjo music, she can play guitar music.
 * Drum-playing - Talented in music, Millie can play the set of drums like a professional.
 * Juggling - Millie was able to juggle five axes during her performance in Camp Ivannakummore.
 * Singing - Like Moxxie, she has a habit of singing whenever she gets very excited.
 * Driving - Millie has a driver skills that is essential for her work, and can even drive aggressively when she crashed into the wedding between Moxxie and Chazwick Thurman.

Gallery

 * Millie/Gallery

Trivia

 * As shown in "The Harvest Moon Festival", she has knives on the side of her and Moxxie's shared bed.
 * In Vivziepop's 2019 short Holidaze as an ornament on a Christmas Tree, there is a tree carved with initials "M+M →B←" in a heart that alludes to her, Moxxie, and Blitzo.
 * While Millie seems to tolerate Blitzo's intrusions, she is not shown to be comfortable with other men flirting with her, as the game attendant pushing Moxxie away and attempting to flirt with her noticeably upsets her.
 * Though, in "The Harvest Moon Festival", she didn't seem to mind and was actually flattered by Striker's attempt to flirt with her.
 * In "The Harvest Moon Festival", it is revealed that she is no longer allowed to participate in the Pain Games because she was responsible for nine out of the fifteen funerals that occurred at the time.
 * It is also revealed that one of her brothers got married at one point, and that she got severely injured while competing over who would catch the bouquet, but in the end Millie managed to do so.
 * In "Truth Seekers", she claims she is about five years older than Loona. If this is true, this places her and possibly Moxxie's age somewhere in her mid or late 20s, as Loona isn’t any younger than eighteen.
 * It was stated in a livestream on April 30, 2022, that in hell years Loona is 22, making Millie roughly 27 years old. It has not been confirmed, however, if Hell years are similar in length to Earth years, which makes their Earth age unknown.
 * It is revealed in "Ozzie's" that she and Moxxie have been married for a year. With the premiere date of the episode being approximately a year apart from the series' first episode, "Murder Family".
 * In "Exes and Oohs" it was revealed on Moxxie's Sinstagram that Millie took his last name after they got married.
 * It is revealed through Blitzo's text history with her in "Seeing Stars" that Millie sends Blitzo pictures of the sex toys she plans on using on Moxxie, asking Blitzo on what he thinks of them.
 * Millie is rarely seen without her choker, even in bed.
 * In a tweet Vivienne Medrano explains that Millie's personality traits are on display but they tend to be upbeat, and that her not coming from pain and trauma, like Blitzo, Moxxie, and Loona do, does not take away from her character.
 * Vivziepop goes on to say that Millie has some fun things coming but she won't have a tragic/dramatic story like the others.
 * According to[Vivienne Medrano, Millie is planned to have more with her as the biggest/sole focus later on, and that she gets her episodes in the second season.
 * In an upcoming episode Millie will sing "a more goofy song".
 * This could be referring to the song "Regular Joe", which is also her first solo song.
 * Millie shares some characteristics of Kayla from Zoophobia. Both are outgoing, romantic and music loving girls. Millie and Kayla have a hard time holding their anger and are willing to get violent and aggressive to hurt their enemies, but also to protect the people they love, especially their boyfriends. Millie and Kayla are combative, capable of mastering melee weapons.
 * Millie's nickname could be a pun on how she is more adept at using melee weapons.

Development

 * Vivziepop had stated that she would change Millie's voice actor once the actual series premieres but would still keep her previous voice actor, Erica Lindbeck, to voice Loona. Later, actress and dancer, Vivian Nixon, was hired to voice Millie, who developed her voice to have a Southern accent.