Flounder Costume
Bring Ariel's loyal, bright yellow fish best friend to life.
Flounder from Disney's The Little Mermaid is a beloved costume choice for Disney fans of all ages, especially as part of a family group theme. The look centers on a bright yellow body with distinct royal blue stripes, fins, and a cheerful finned headpiece. Whether you choose a cozy plush jumpsuit or a quick DIY tunic, this vibrant underwater look is instantly recognizable.
- Difficulty
- Easy
- Time
- ~30 min
- Budget
- $20–60
Try it on
See yourself as Flounder
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.
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What you need for a Flounder costume
Short on time? Buy it ready-made
Spirit Halloween sells the complete Flounder costume — one box instead of 4 pieces.
Yellow bodysuit or tunic
A bright yellow long-sleeve shirt, hooded sweatshirt, or plush tunic to serve as the fish body.
DIY: Use a plain yellow oversized t-shirt and cut the bottom hem into a rounded shape.
Blue felt sheets
Stiff royal blue felt to create Flounder's signature stripes and fins.
DIY: Cut vertical stripes and fin shapes from an old blue t-shirt.
Yellow pants or leggings
Comfortable, solid yellow leggings or sweatpants to complete the base layer.
DIY: Use plain white leggings dyed yellow with fabric dye.
Finned headpiece
A yellow hood or headband featuring a prominent royal blue felt fin standing upright.
DIY: Hot glue a double-sided blue felt fin to a standard yellow plastic headband.
Rather not assemble it? See ready-made Flounder costumes at Spirit Halloween ↗
How to put it together
- 1
Put on the yellow long-sleeve shirt or sweatshirt and matching yellow leggings.
- 2
Cut several tapered, horizontal stripe shapes out of royal blue felt, making them wider at the back and pointed toward the front.
- 3
Attach the blue felt stripes to the sides and back of the yellow shirt using fabric glue or safety pins.
- 4
Cut out two large pectoral fin shapes from blue felt and attach them to the sides of the waist or sleeves.
- 5
Construct the headpiece by gluing a large, upright blue dorsal fin to a yellow headband or the hood of your sweatshirt.
- 6
Finish the look with comfortable yellow or neutral sneakers.
Makeup & hair
Keep makeup simple with a touch of blue eyeshadow or face paint scales on the temples. If not using a hood, style hair in a high ponytail or faux-hawk sprayed with temporary blue hair color to mimic Flounder's dorsal fin.
Flounder for couples, groups, kids & more
- couples
- Pair up with Ariel in her classic green mermaid tail and purple seashell top.
- group
- Form a full Little Mermaid group with Ariel, Prince Eric, Sebastian, and Ursula.
- kids
- An adorable plush yellow zip-up onesie with built-in blue felt fins and a padded hood.
- Plus size
- A loose-fitting yellow fleece poncho or oversized hoodie decorated with blue felt stripes offers a comfortable, breezy fit.
- pet
- A yellow dog vest with blue felt stripes fabric-glued to the sides and a small soft fin on the back.
More ways people search for this costume
The most-searched variations of “Flounder costume”, and how this look adapts to each.
Flounder costume dog
- A yellow dog vest with blue felt stripes fabric-glued to the sides and a small soft fin on the back.
Tips
- For outdoor trick-or-treating, use a yellow hooded sweatshirt as your base to keep warm.
- If making felt fins, double layer the felt with a piece of cardboard or craft wire inside so they stand upright instead of flopping.
- Keep the stripes on the back and sides of the torso to keep the front clean and comfortable when sitting down.
Flounder costume FAQ
- What color is Flounder from The Little Mermaid?
- Flounder is bright yellow with royal blue stripes on his sides and matching royal blue fins.
- How do you make a DIY Flounder costume?
- Start with a yellow sweatshirt and leggings, then cut stripes and fins out of royal blue felt and fabric-glue them to the sides and hood.
- Is Flounder a good costume for babies?
- Yes, a plush yellow bunting or romper with blue felt accents is incredibly popular, comfortable, and warm for infants.
Did you know? Despite his name, Flounder is not actually a flounder; he is a tropical yellow-and-blue colored fish, resembling a damselfish or a juvenile Atlantic blue tang.