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.

So here are my instructions after actually making this costume! It should take you a few hours to complete.

Step 1: Supplies

Here's what you'll need:

1 largish hat
1 3' x 3' piece of cardboard
1 yard of sparkly blue fabric
1 yard of blue fleece or felt
10 yards silver ribbon
10 yards white ribbon
1 roll of bubble wrap, large or small bubbles will both work
Led christmas lights & batteries
1 roll of duct tape
Stapler

Step 2: Make the Hat

Depending on the size of your costume wearer, cut the cardboard to fit around the hat.

Step 3: Add Felt for Underneath the Jellyfish

Lay it over the felt, then staple it to the edges of the cardboard.

Cutout the felt underneath where your head goes.

Step 4:

Add bubble wrap to fill the areas around the hat.

Staple the duct tape to hold it in place.

Step 5: Make Your Tentacles

Cut the lengths of ribbon you want. We also used the bubble wrap for fun. You can get really creative here with all kinds of ribbons, curls, colors, go nuts!

Step 6: Attach Your Tentacles

Again, use your stapler to attach the tentacles.

Step 7: Light It Up!

We also had some pillow filling, so I added that as well.

Lay the lights around the hat with the battery unit in the middle of the hat. You will be able to turn it on and off through the fabric.