Last updated: May 24, 2026·🔄 Guide reviewed and refreshed ahead of Halloween 2026.· By Seckin Peker

Halloween Costume Guide

Millie Helluva Boss Halloween Costume Guide

Red Skin  ·  Black Horns  ·  Yellow Eyes

Five items to build Millie’s look, plus the body paint situation you need to plan for in advance.

Helluva Boss Hazbin Hotel Demon Animated Assassin Body Paint Dark Feminine Yellow Eyes
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Quick Answer: Millie’s Halloween costume needs body paint as a base layer. Plan for that before anything else.
  • Helluva Boss Millie Costume Set (essential)
  • Red Body Paint (essential)
  • Devil Horn Headband
  • Yellow Sclera Contact Lenses
  • Temporary Tattoo Marker (optional)

Millie kills people for a living and finds it genuinely enjoyable, which is the entire basis of her personality in Vivziepop’s adult animated web series Helluva Boss. The red body paint is the one item that makes this costume work as Millie rather than a generic demon. Recognition is solid at animation fan events; at a general Halloween party, anyone under 30 who watches adult animation on YouTube will probably get it, and everyone else will assume you are just a red demon.

Items Total5 Items
DifficultyMedium
VibeHellish Powerhouse
Cost$40–$100

Millie Halloween Costume Items

Millie Helluva Boss Halloween costume guide infographic showing five numbered items: black crop top set with tail and gloves, black demon horns, yellow sclera contacts, red body paint tube, and temporary tattoo marker

Millie Costume Items

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Millie Helluva Boss Vivziepop Demon Costume
  • 1 Helluva Boss Millie Costume Set (essential) This set is what makes the costume Millie and not just a red demon in black clothes. The choker and heart tail are the specific details fans will check for. The cropped top runs small on some builds, so check the size chart before ordering; a top that pulls across the chest at a party is not something you can fix on the night.
    See on Amazon
  • 2 Devil Horn Headband Millie’s horns are thin with a white stripe. Most headbands come solid black, which is close enough. A thin stripe of white face paint on the horn takes about 30 seconds if you want the accurate version.
    See on Amazon
  • 3 Yellow Sclera Contact Lenses Sclera lenses cover more of the eye than standard colored contacts and take longer to get comfortable. Only buy from FDA-registered retailers. Do not sleep in them.
    See Deal
  • 4 Red Body Paint (essential) Without red skin, this is a black outfit with horns, not Millie. Apply it to all visible skin before putting the costume on. Use a setting spray or the paint will transfer onto the fabric, other people, and anything you lean against. Budget 30 to 45 minutes for application, drying, and setting.
    See on Amazon
  • 5 Temporary Tattoo Marker (optional) For Millie’s white spots on the upper arm, upper left leg, and tail. Skip it if you are not doing a screen-accurate build; the costume reads fine without them.
    See on Amazon
Millie from Helluva Boss in her black cropped outfit with red skin, small black horns, and a pointed tail

How to Style the Millie Halloween Costume

The red skin is the first thing people read, and patchy or already-transferring paint by the time you arrive makes the whole costume look rushed. If the body paint is not set properly, the black outfit underneath reads as the costume and the red reads as a mistake. Apply in thin even layers, let each one dry, and seal with setting spray before the clothes go on.

Millie smiles at things that would alarm most people. Someone pulls a weapon at a party scene in the show and her immediate reaction is visible excitement. If something goes wrong at the party and everyone else tenses up, staying visibly pleased about it is the most in-character thing you can do.

Red paint will end up on everything you touch

Even well-set body paint transfers under the right conditions: a crowded room, prolonged contact, or leaning against something for too long. Test the setting spray on a patch of skin before the night, bring a travel size for touch-ups, and accept that one white wall or white shirt will not survive the evening. Tell people near you before you hug them.

Sclera contacts need time before you leave

Put them in at least 15 minutes before you need to walk out the door. Sclera lenses are wider than standard contacts and the adjustment period is real. If they are still causing discomfort after 20 minutes of wear, take them out. The costume works without them and an irritated eye for the rest of the night is not worth the accuracy.

Millie Group Halloween Costume Ideas

Couples Idea

Millie & Moxxie

Excellent couple pairing because the dynamic is built into the show: they are married, they work together, and they bicker constantly while being completely devoted to each other. The visual contrast between Millie’s red skin and Moxxie’s white-and-black imp design reads clearly side by side. Anyone who knows Helluva Boss will get it immediately.

Millie (you) Moxxie

Duo Idea

Millie & Loona

Strong duo if both costumes are well-executed, because the contrast is hard to miss: a small cheerful red imp next to a tall sullen white hellhound. They do not have much direct chemistry in the show, but visually the pairing works and fans of the series will place both characters without any explanation needed.

Millie (you) Loona

Group Idea: Hell’s Hired Guns

Millie, Blitzo, Moxxie, Loona, Stolas

Excellent group for a Helluva Boss fan crowd, because the visual variety is genuinely distinct: a red imp assassin, a white hellhound, and a tall owl demon are not costumes that blur together. Outside of animation fans, this group needs explaining. The I.M.P. squad only works if everyone goes full character; half the group dressed as “just a demon” breaks the whole concept.

Millie (you) Blitzo Moxxie Loona Stolas

Group Idea: Animated Underworld Assassins

Millie, Harley Quinn, Jinx, Marceline, Raven, Toph Beifong

Might work, but the connection is thematic rather than from a shared universe. Harley, Jinx, and Raven carry the group’s recognition for anyone who does not know Millie. Toph Beifong fits the energy but requires the crowd to connect characters from six different shows as an intentional group rather than a coincidence.

Millie (you) Harley Quinn Jinx Marceline Raven Toph Beifong
Millie from Helluva Boss full-body pose with red skin, small black horns, and pointed tail, wearing her black overall-style outfit

Millie Halloween Costume DIY Tips

Body Paint: What Actually Works

This is not a step you can rush on the day. Most Millie costumes that look bad in photos come down to the body paint, not the outfit.

  • Thin layers. Let each one dry before the next. Thick single-coat paint cracks when you move.
  • Makeup sponge for large areas; brush for edges and details.
  • Setting spray: not optional.
  • Face, neck, hands, and visible midriff only. The costume covers the rest.
  • Makeup wipes for cleanup. Something will go wrong.
  • Skip glitter over the paint unless you want it on everything you own for the next week.

Acting the Part

Millie is cheerful about things that should be alarming. She does not play scary; she plays enthusiastic. The contrast is the joke.

  • “It’s Millie time!” right before doing something completely mundane. Deadpan delivery, full commitment.
  • When someone asks what you do for work: “assassin,” said brightly, no follow-up.
  • Mid-action pose for photos. Millie never just stands there.
  • Drop “Let’s kill this rich guy!” if anyone complains about the drink prices. Wait for the correction: “I didn’t say with my hands!” The pause is the whole joke.
  • Skip the scary demon energy entirely. Wrong character.

All Hazbin Hotel and Helluva Boss Cosplay Ideas

Every guide we have for the Vivziepop universe, in one place.

Alastor the Radio Demon from Hazbin Hotel in his red tailcoat and top hat holding his microphone staff

Alastor

Hazbin Hotel

Angel Dust from Hazbin Hotel in his white spider-demon form with pink bow tie and multiple arms

Angel Dust

Hazbin Hotel

Charlie Magne the Princess of Hell from Hazbin Hotel smiling in her red and black suit

Charlie Magne

Hazbin Hotel

Vaggie from Hazbin Hotel with silver hair, an X-shaped eyepatch marking, and her pale uniform

Vaggie

Hazbin Hotel

Cherri Bomb from Hazbin Hotel with one eye, blonde pigtails, and explosive bombs

Cherri Bomb

Hazbin Hotel

Tom Trench from Hazbin Hotel in his news anchor suit with a gas mask over his face

Tom Trench

Hazbin Hotel

Katie Killjoy the spider demon news anchor from Hazbin Hotel in her purple blazer with her sharp smile

Katie Killjoy

Hazbin Hotel

Egg Bois from Hazbin Hotel, small round egg-shaped demon minions with tiny limbs and top hats

Egg Bois

Hazbin Hotel

Niffty from Hazbin Hotel, a small one-eyed demon in a 1950s housewife dress holding a knife

Niffty

Hazbin Hotel

Lucifer Magne from Hazbin Hotel in his white suit and top hat holding his rubber duck cane

Lucifer Magne

Hazbin Hotel

Millie from Helluva Boss with red skin, black horns, and her black crop top and ripped pants

Millie

Helluva Boss

Loona the hellhound receptionist from Helluva Boss with white fur, red eyes, and gothic outfit

Loona

Helluva Boss

Moxxie from Helluva Boss in his imp form wearing a red and black suit with white polka dots

Moxxie

Helluva Boss

Striker from Helluva Boss in his cowboy assassin outfit with a wide-brim hat and long coat

Striker

Helluva Boss

Millie Halloween Costume: FAQ

You need five items: the Millie costume set (crop top, ripped pants, gloves, choker, tail, heart tattoo stickers), a devil horn headband, yellow sclera contacts, red body paint, and optionally a temporary tattoo marker for the arm spots. The costume set and the red body paint are the two essential pieces. Without the red skin, the costume reads as a generic demon rather than Millie specifically.

  • “It’s Millie time!”
  • “Let’s kill this rich guy!” (followed by: “I didn’t say with my hands!”)
  • “If you want my husband, you’re gonna have to fucking KILL me!”

The second one is the most usable at a party. Say the first half with complete enthusiasm, then pause before the correction. The timing is the whole joke.

Yes, within the right crowd. Helluva Boss has a dedicated and active fanbase, and recognition is high at animation-adjacent events or parties skewing toward fans under 30. At a general Halloween party, expect some people to not place it, but anyone who knows the show will recognize you immediately.

Not strictly required, but they are the detail fans will notice first. If you are wearing full red body paint and skipping the contacts, the look feels slightly unfinished to anyone who knows the character. Only buy from FDA-registered retailers, and never wear contacts longer than the package recommends.

Paint only what will be visible. Millie’s outfit covers most of her body, so face, neck, hands, and any exposed midriff is all you need. Full body paint adds significant cleanup time for no visible benefit.

Millie is from Helluva Boss, an adult animated web series created by Vivziepop and available free on YouTube. It follows the I.M.P. assassination company operating out of Hell. It is a separate show from Hazbin Hotel, though both are by the same creator and set in the same universe.

Millie is voiced by Vivian Nixon in the main series. A different voice actress performed the role in the original pilot before the show was formally produced.