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I made this jellyfish costume for my wife during on our Halloween build day here at Instructables. It turned out to be a great lesson on the value Instructables brings to the Internet. The costume idea came from a few costume sleuthing searches, probably some Pinterest results, and then onto an unnamed large corporate site with a pretty picture. I tried to follow what looked like reasonable instructions, only to find out that whomever was writing these instructions had never actually made the costume.

If you are looking for a fun, easy and clever costume this year, then we have got you covered! This fun DIY Jellyfish Costume can be made quickly for a last minute costume emergency or for if you have a lot of parties this month and not a lot of crafting time. Plus, it’s a no sew costume so you’re little one can help you make it! My friend G Dupree created this adorable costume for her daughter and we just loved it and had to share!

Started with the cowboy hat (sombrero seemed to flimsy as I wanted to be able to move about and dance easily).
Cut foam board in a 20 inch diameter circle (this was pretty large- I would do smaller next time, maybe 18 inches). Then cut a close fitting hole in the foam board for the top of the hat to fit through (foam board is sitting on top of hat). I cut carefully each time to ensure the hole and hat fit my head closely.

I then applied hot glue around the top of the cowboy hat rim and firmly pressed the foam board circle onto it. I poked a hole from underneath on each side of the hat in order to thread the battery operated light wire through from underneath the hat. Hot glued and adhered the 3 tap on lights underneath and behind where my head would fit – these make the large tentacles.

I covered the top of the hat with white duct tape and then glued metallic tissue all over the top and underneath of the hat. I also taped some of the colored tissue over each of the tap on lights. I used blue for one jellyfish and pink for the other one.

Items Needed

One clear umbrella
Packing bubble wrap (We used green for the a more dramatic effect.)
Clear Packing Tape
2-4 Sets of Battery Operated Lights in Pink, Clear or Any Other Color
Iridescent Fabric-approximately 2.5-3 yards
White clothing was chosen for safety purposes, but you can also do blue, green or black with reflective tape


Wrap the bubble wrap tightly around the umbrella and secure it on the inside with clear packing tape. Use two sheets in each direction and cross them so you have full bubble wrap coverage.

Cut two pieces of iridescent fabric, one piece 3 feet long and the other piece four feet long. Then wrap the fabric over the bubble wrap covered umbrella, crossing over each other, and secure it inside with clear packing tape.

Cut wide strips out of the remaining fabric to make varying lengths of tentacles and tape on the inside of the umbrella.Step 4: Wrap and tape the lights on the inside of the umbrella. Batteries are secured up inside the frame of the umbrella.

You could also substitute the umbrella for a wide brimmed hat so that your little one wouldn’t have to carry the umbrella.