Picture of Halloween LED Jellyfish Costume
EDIT - I'm actually selling this costume now as I need space back! details on my blog

This is a visually stunning fancy dress costume using LED rope lights and a plastic washing basin to create a deep sea bioluminescent jellyfish thing.

Perfect for Halloween, or any party where it's going to be dark. People will stop in their tracks to start dancing round you, or simply have a spasm. You will feel like a total attention whore, but you will love it too.

Remove these adsRemove these ads by Signing Up

Step 1: Summary

Picture of summary
You are going to get a plastic basin, and use glue and cable ties to secure a load of LED rope lights to the inside, then (optionally) rewire them to a central power supply. You make it wearable by cable tying a skateboard helmet to the inside of the translucent basin.

Step 2: LED rope necklaces

Picture of LED rope necklaces
These are the LED rope light necklaces. They are the kind that street vendors sell to kids at bonfire parties or street festivals (mardi gras?) for a couple of quid (3-5 USD). I guess there are many kinds, but the kind I found run of 3 x 1.5V button batteries, and are controlled by an electronic push button on/off switch.

you can buy them here in the uk

here in the US
multicolor tube necklace

Step 3: Mount the LED ropes to the basin

Picture of mount the LED ropes to the basin
I got a translucent (this is important, so light glows through it) basin from a pound shop (dollar store). it was about 50cm diameter, which is an ok size. for 18 tentacles.

I used hot glue to mount the battery end of the lights to the inside of the basin.
Use sandpaper to rough the surfaces first, then clean them thoroughly so it sticks better. people WILL pull your tentacles.

Leaving 5cm of plastic tube inside the basin. This will let you use a cable tie around this soft bit of the rope and leave everything nice and secure.

1-40 of 70Next »
shuberty5 years ago
I made this for my 6 year old son for Halloween - was a huge hit. People stopped us and took pictures as we went down the street. Only suggestion was to not put the LED strings in front of his face - I think he was seeing the blinking lights in his sleep for a few days. I think next year I'll make another, so my two sons can be a "swarm".
deadinsect (author)  shuberty2 years ago
very late reply! a group of jellyfish is actually called a "smack" ... :)
Powerhouse7 years ago
excuse me I am new to this Instructables thing and I have a budget. might I ask how much this will all cost? I thank you a lot for this project, I like LED things.
I LOVE this jellyfish hat!!! Planning on making one this year to wear to Bear Creek Music Fest in November....I am also on a budget & the LED strands seem to be quite pricey...have you had any luck finding a good deal/alternative?
I built this for less than $50, the link that he used for the US is the best deal I have found. I ordered about 25, assuming some would be broken. I couldn't find a basin so I made a dome of Knex building pieces and covered it in a trash bag. Good luck!
cchambers33 years ago
Hi I love this idea and perfect for a marine theme for a festival coming up. Do you know the best place to buy the light ropes? I found Alter e glow best price but not sure if they are long enough. Thanks! :)
maheesa4 years ago
For wiring the positive terminal, do you solder to the spring?
deadinsect (author)  maheesa4 years ago
I did, yeah
sewer726 years ago
I'm in a deep-water aerobics class. Would this work in a pool?
like not at all, electricity+water=no!
ajam1235 years ago
More like an instant seizure costume... ;P
ckdkjunk5 years ago
This is awesome. I will be adding these LED lights to my son's rocket ship costume. If I wire as instructed...will all the LED strands flash at the same time and in the same pattern or will they be flashing out of sync with each other, as they would if I just turned them all on independently? Thanks for your post. Excellent!
deadinsect (author)  ckdkjunk5 years ago
when you switch them all on together, they start all in sync for a few seconds, then get slowly out of sync due to variations in each strand...! if you were a stickler for wanting them to "wave" in sync you could build a timing circuit that turned the power on and off about once a second.... either way it looks cool....! enjoy
sibiria5 years ago
This is so awesome!!! If I am going to halloween party this is my costume :)
I have been browsing this site for months and this is probably the most awesome -ible I've come across. Sooooooo creative, fun, amusing, and cute! Thank you.. I now have something to wear on my 21st birthday. :)
daphnegirl6 years ago
Hi, Just wanted to send you some pix of my jellyfish costume from this past H'ween that was inspired by yours -- I simplified it by using glow-necklaces duct-taped to a salad bowl 'cause the word "solder" is not in my vocabulary :) The pix are kinda crap 'cause every other one was taken with the flash on, rendering me just some dork with a bowl on her head. Looked GREAT in the dark, though! Thank you SO much for the inspiration; everyone dug it! Cheers! Joanie
deadinsect (author)  daphnegirl6 years ago
thanks! pics with flash do look really stupid, I shold have warned people about that in the text! ant
jasmines6 years ago
This is awesome. I love it!
chakuseki6 years ago
This costume was the most fun I've had at Halloween, the people loved it here in DC. I'll put up some pics when I get em. Thanks again deadinsect!
xand3r6 years ago
I made this for Halloween this year. Everyone loved it, thanks for the idea!

I got a $6 hard hat from Home Depot, removed the innards, and hot glued some sponges to the inside (otherwise the hard hat sat too high).
Also didn't bother with the zip ties, just hot glued the heck out of it, which worked fine. In fact, I burnt out a couple during wiring and couldn't remove them! Ended up just cutting the bad tentacles off and gluing on more next to them.

Best costume idea ever, thanks so much! What are you planning next??

gsurov6 years ago
just made mine for halloween on friday! need to find a white jumpsuit. but can't wait to get out roaming the streets in nyc and inducing a dance floor seizure! wear you're sun glasses.
pedaleo7 years ago
Can you please help me with details on doing the electrical connections. I'm not very good at this...
deadinsect (author)  pedaleo7 years ago
hi pedaleo - can you be more specific? the wiring up of the jellyfish is fiddly and time-consuming, but the electronics behind it is very simple - all the lights are re-wired in paralell - if you aren't sure what this means I think you should probably find someone who can explain in person, as it's quite a lot to explain over the internet....!
I absolutely love this idea. :) Any idea how long the batteries in those necklaces last? I'm trying to decide if I just want to risk using batteries alone... I would probably just use it for Halloween, so would just need it for one night. Thanks!
deadinsect (author)  crbnmnxide7 years ago
I think you would get away with it for 6 hours or so?! ant
Ok i hooded everything up right. But the batteries seem to get very hot.
Pedaleo, I think I can help you. Just connect all the bottom terminals of the LED ropes with wires together then repeat with the top ones. The two end terminals go as follows: one goes to the switch and the other goes to the battery pack. Do not use a pushbutton switch.
miaou6 years ago
is the "connect all the LEDs together" step necessary, or could you just put batteries in each of the individual light strands?
deadinsect (author)  miaou6 years ago
you can do that. the strands all come with batteries. Each one lasts about one night - 6 hours?
Thanks to you, I now have a costume idea for a halloween party I'm organizing :D Do you have any other less helmety options for the basin? Like some kind of hat that ties around the head. Or do you think it would weigh too much if there was no helmet?
I think women would look great in these too.
deadinsect (author)  WonderWheeler6 years ago
I was just at a music festival (bestival) in the UK, and loads of people had made these. chicks do look good in them.
(removed by author or community request)
pretty mauled, but just double cable tie them and go with them. On the LED ropes I had, there is a small circuiot board at the top of the rope - make sure this can't bend by having it above the first cable tie. If it's a hardcore dance party (like an electronic music rave) then people will be quite friendly grabby rather than aggressive grabby and it's all fine. unless hardcore has a different meaning than I think!? go for it.
pjak6 years ago
This looks mint! As Im sure youre aware this years Bestival theme is 30000 freaks under the sea- question is can I nick your idea or are you using it this year? Great costume Paul
deadinsect (author)  pjak6 years ago
go for it. am going to rent or lend it someone though. more fish the merrier, ant
fernandonh6 years ago
I just ordered the LED ropes online... I just need to get out there and find myself a nice basin. Thank you for the great costume idea. I will be wearing at Burning Man this year and I have a feeling it's going to be a success!
deadinsect (author)  fernandonh6 years ago
my friends are going all the way to burning man from the UK - I'll tell them to look out for jellyfish!!!
That would be awesome... tell them to look for me. I bought the tentacles but I am having a hard time finding a decent basin. I will figure something out. You should come to burning man Deadinsect!
Shifrin7 years ago
Sweet, That is Awesome!
1-40 of 70Next »