Undertale Costume
Bring the lazy, pun-loving skeleton of Snowdin to life.
Undertale is a beloved indie RPG, and its most iconic character, Sans the Skeleton, is a massive favorite for cosplay and Halloween. His look is incredibly comfortable, instantly recognizable, and easy to put together. This guide focuses on Sans's classic outfit, featuring his signature blue hoodie, black shorts, and skeleton features.
- Difficulty
- Easy
- Time
- ~20 min
- Budget
- $30–80
Try it on
See yourself as Undertale
One clear photo of yourself; we render you in this costume — face untouched, full body, about 20 seconds.
One render, $1. No account needed — if it fails you're not charged. Pricing.
Your photo is sent to Google's Gemini API to make the render and isn't used for training. Renders are AI-generated and labelled.
Want a different costume on this photo, or a whole group in costume? Open the Try-On Studio.
What you need for a Undertale costume
Short on time? Buy it ready-made
Spirit Halloween sells the complete Undertale costume — one box instead of 6 pieces.
Blue zip-up hoodie
A bright, medium-blue zip-up hoodie, ideally with a white fleece or faux-fur lining in the hood.
DIY: Use any plain blue hoodie and fabric-glue white felt trim around the hood opening.
Black basketball shorts
Loose-fitting black athletic shorts featuring a vertical white stripe down each side.
DIY: Take plain black shorts and fabric-glue white ribbon down the sides.
White skeleton mask
A molded plastic or fabric mask depicting Sans's wide, static toothy grin and large hollow eye sockets.
DIY: Draw Sans's face on a white paper plate, cut out the eye holes, and attach an elastic band.
White t-shirt or turtleneck
A plain, solid white t-shirt or turtleneck sweater to wear underneath the open hoodie.
Black leggings or tights
Opaque black leggings or skeleton-print tights to represent skeletal legs beneath the shorts.
Pink slip-on slippers
Fluffy, plush pink bedroom slippers to capture his relaxed, lazy aesthetic.
DIY: Use plain white sneakers if you do not have pink slippers.
Rather not assemble it? See ready-made Undertale costumes at Spirit Halloween ↗
How to put it together
- 1
Put on the plain white t-shirt or turtleneck as your base layer.
- 2
Pull on the black leggings or tights to mimic skeletal legs.
- 3
Slip the black basketball shorts on over the leggings.
- 4
Put on the blue zip-up hoodie, leaving it unzipped halfway to show the white shirt underneath.
- 5
Put on the Sans skeleton mask, ensuring the eye holes align comfortably.
- 6
Slide into the pink slip-on slippers to complete the laid-back look.
Makeup & hair
If you prefer not to wear a mask, apply white face paint over your entire face, use black face paint to create large circles around your eyes, and draw a wide, toothy grin. For an extra touch, paint one eye socket entirely black and add a single glowing blue dot in the center.
Undertale for couples, groups, kids & more
- couples
- Pair up as the skeleton brothers with one person dressing as Sans and the other as Papyrus in his red scarf and battle body.
- group
- Form a full Undertale party with friends dressing as Frisk in a striped shirt, Toriel in a purple robe, and Papyrus.
- kids
- A blue hoodie, black shorts, and a lightweight plastic skeleton mask make this a warm and comfortable choice for trick-or-treating.
- Plus size
- The oversized hoodie and elastic-waist basketball shorts offer an incredibly comfortable, adjustable, and size-inclusive fit.
- pet
- Dress a small dog in a tiny blue dog hoodie to be your miniature skeleton sidekick.
Tips
- Keep your hands in your hoodie pockets to perfectly capture Sans's relaxed, lazy posture.
- If you want to reference his famous boss fight, place a small blue LED light inside one eye socket of your mask.
- This costume is exceptionally warm and comfortable, making it perfect for cold Halloween nights or long convention days.
Undertale costume FAQ
- What shoes does Sans wear?
- Canonically, Sans wears pink bedroom slippers, though some official art and fan interpretations show him in simple white sneakers.
- How do I make a DIY Sans mask?
- You can use a white paper plate or lightweight craft foam, cut out the eye holes, draw his signature wide grin with a black marker, and attach an elastic band to the back.
- What color is Sans's hoodie?
- Sans wears a bright, medium-blue zip-up hoodie, often depicted with a white fluffy lining or hood trim.
Did you know? Sans is named after the Comic Sans font, which is also the typeface used for his dialogue text boxes in the game.