Millie

Millie (full name Mildred) is a main character in Helluva Boss who is Moxxie's wife and works at I.M.P as an assassin.

Appearance
Millie is a red demon with a long, demonic tail with white markings. She has eyes made up of yellow sclera and black pupils. Her hair is short dark purple. She has long black eyelashes that extend past the sides of her hair. She has two black horns with three thin white stripes and grayish black hair with a white spot in the center, and a fringe that covers the middle of her right horn.

She wears black lipstick, wears a simple black choker, a cold shoulder black blouse with gold buttons where the straps at the top meet the torso, ripped black pants, black fingerless gloves, and black footwear that does not cover the tips of her hoof-like feet. Millie also has a black heart-shaped tattoo on her left shoulder and two white spots on the inside and outside of each of her elbows.

Personality
Millie is very cheerful most of the time. She often shows a smile on her face and rarely does nothing. She is outgoing and is not afraid to speak her mind, whether it's to express her emotions or just turn to see a coworker. She seems to enjoy her work as an assassin, as it can be seen that she is very harsh and violent to kill her victims; According to Moxxie, she is aggressive in both looting and her work. Also, Millie is affectionate with Moxxie and she often comforts, calm or defend him when necessary.

Background
Millie married Moxxie and together they were hired to work at I.M.P. under the direction of Blitzo. Although Millie enjoyed murdering people, she noticed that Moxxie felt frustrated, even more so when she killed Eddie, who was the wrong target of a mission and they barely managed to save him. Millie tried to calm him down, until Loona recanted and claimed that Eddie was the target, to which Blitzo decided to shoot him, and Millie helped him tear his body apart to return Eddie to Earth.

Blitzo
Blitzo and Millie seem to have a nice relationship. Unlike her husband, Millie agrees with some of Blitzo's ideas and laughs when she finds it in her fridge, not thinking it is a big deal.

Moxxie
Moxxie is Millie's husband and coworker. The two have a positive relationship, as they are shown cooking together and singing "Oh Millie" to each other and almost kissing before being interrupted by Blitzo.

Loona
Loona and Millie don't seem to get along, as even Millie insulted her and raised her middle finger when Loona confronted Moxxie.

Trivia

 * Millie seems to have a slight southern accent.
 * There is a large photograph of what could be Moxxie and Millie's wedding in the meeting room. There, Blitzo drew himself with a red marker to make it look like he was hugging them.
 * In Vivziepop's short Holidaze, there is a tree carved with the initials "M + M → B ←" in a heart, which alludes to Millie and Moxxie (and by extension Blitzo).