Cereal Killer Costume
A killer pun costume that is incredibly easy to DIY.
The Cereal Killer costume is a classic, pun-based Halloween favorite that plays on the words 'serial killer.' It is a popular choice for those who want a funny, low-effort costume that gets immediate laughs. The look consists of a plain t-shirt decorated with mini cereal boxes pierced by plastic knives and splattered with fake blood.
- Difficulty
- Easy
- Time
- ~30 min
- Budget
- $15–40
Try it on
See yourself as Cereal Killer
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What you need for a Cereal Killer costume
Short on time? Buy it ready-made
Spirit Halloween sells the complete Cereal Killer costume — one box instead of 6 pieces.
White T-shirt
A plain, inexpensive white cotton crewneck t-shirt that you don't mind getting stained.
DIY: Use an old white t-shirt or sweatshirt from your closet.
Mini Cereal Boxes
An assortment of variety-pack miniature cereal boxes.
DIY: Print out miniature cereal box templates and fold them from cardstock.
Plastic Knives
Silver-colored plastic toy knives or standard plastic kitchen knives.
DIY: Cut knife shapes out of stiff cardboard and paint the blades silver.
Fake Blood
A bottle of red liquid fake blood or red fabric paint for a permanent look.
DIY: Mix corn syrup, red food coloring, and a splash of blue food coloring.
Safety Pins or Hot Glue
Used to secure the cereal boxes and plastic knives firmly to the shirt.
DIY: Use strong double-sided mounting tape.
Plastic Spoon Necklace
A plastic spoon tied to a string or ribbon to wear as a funny accessory.
DIY: Drill a small hole in a plastic spoon handle and thread yarn through it.
Rather not assemble it? See ready-made Cereal Killer costumes at Spirit Halloween ↗
How to put it together
- 1
Lay the white t-shirt flat on a protected work surface, placing cardboard inside the shirt to prevent glue or blood from seeping through to the back.
- 2
Carefully stab a plastic knife through the front of each mini cereal box so it looks impaled.
- 3
Arrange the stabbed cereal boxes across the front of the t-shirt in a scattered pattern.
- 4
Use hot glue or safety pins from the inside of the shirt to securely attach the boxes and knives to the fabric.
- 5
Drizzle fake blood or red fabric paint generously over the boxes, knives, and the surrounding areas of the shirt to simulate splatters.
- 6
Let the shirt dry completely before putting it on.
- 7
Put on the shirt, hang the plastic spoon necklace around your neck, and carry an extra spoon as a prop.
Makeup & hair
Keep your hair and makeup simple, or go for a slightly disheveled look with dark under-eye circles using eyeshadow to play up the 'killer' theme.
Cereal Killer for couples, groups, kids & more
- couples
- One person goes as the Cereal Killer, and the other dresses as a giant spoon or a milk carton.
- group
- A group can dress as different 'cereal killers,' each choosing a specific cereal brand theme (e.g., Captain Crunch, Tony the Tiger, or Lucky the Leprechaun) with fake weapons.
- kids
- A kid-friendly version can use felt knives instead of plastic ones and red fabric paint instead of realistic fake blood to keep it lighthearted.
- Plus size
- Use an oversized white t-shirt or hoodie to provide a larger canvas for attaching the mini cereal boxes comfortably.
- pet
- A small dog sweater decorated with a single felt mini cereal box and a felt knife.
Tips
- If using hot glue, make sure it cools completely before wearing the shirt so the heavy boxes don't sag.
- Use red fabric paint instead of real fake blood if you want the costume to be reusable, as fake blood can remain sticky and rub off on surfaces.
- Keep a few extra safety pins on hand in case a box starts to pull away from the fabric during your event.
- Wear dark pants or jeans so any accidental drips of fake blood blend in easily.
Cereal Killer costume FAQ
- How do you attach the cereal boxes to the shirt?
- You can use a hot glue gun to attach the flat backs of the mini boxes directly to the shirt, or secure them from the inside using heavy-duty safety pins pushed through the cardboard.
- Is this costume school-appropriate?
- Because it features fake weapons and blood, some schools may not allow it. You can make a school-friendly version by replacing the knives with plastic spoons and using colorful glitter instead of fake blood.
- Can I reuse this costume?
- Yes, if you use permanent red fabric paint instead of corn-syrup-based fake blood, the shirt can be stored and worn again next year.
Did you know? This costume is one of the most famous examples of a 'punny' Halloween costume, relying on a simple play on words that has remained popular for decades due to its low cost and high recognition.