Introduction: Halloween LED Jellyfish Costume

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.

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.

Step 4: Tentacles in Place

Picture of Tentacles in Place

wow, ok done.

I also put 3 LED rope lights in the top of the basin to light the bell of the jellyfish. If I did it again, I would do more lights in the basin, as it really adds to the effect.

I used even more hot glue to fill all the gaps between the LED rope lights and the basin, before tightening up the cable ties. I'm glad I did this because a bunch of girls in a dance tent utterly mauled my tentacles, but it all held together.

Step 5: Wiring It

Picture of Wiring It

I now pulled all the batteries out the rope lights, and used a naked solid wire to go through all the negative terminals of the lights. I soldered it to each terminal, then hot-glued it in place so it wouldn't go anywhere. I then repeated the process for the positive terminal. Remember to glue it all in place so it won't go anywhere - if the 2 wires touch, it shorts everything out.

bascally, you are wiring all the rope lights together in paralell.

Step 6: Control Box and Power Supply

Picture of Control Box and Power Supply

this bit is optional. I used a switch with three positions : locks-on / neutral-off / temporary-on

you don't need this and wiring a simple on-off switch is fine.

I then hooked it all up to a 3 D-cell battery pack. I knew this was overkill, in terms of how much charge I'd need, but i was at a festival for a whole 4 days and didn't want to take any chances. you could probably get away for 3xC-cells or even 3xAA cells for a long night.


you put the 3 cells in series, to make 1.5V x 3 = 4.5V

then you put all the rope lights in parallel.

Step 7: Mounting It

Picture of Mounting It

you get any comfortable helmet with holes in the top, then drill corresponding position holes in the basin , and use hot glue and cable ties to mount it on.

I then glued the control box to the back of the helmet, and ran ries down the battery pack on my belt. This is because I was worried about ahving too much weight on my head.

If you were using C or AA cells though, I think you could mount them on the helmet too, and probably not sustain lasting neck damage.

Step 8: Done

Picture of Done

there you go, done! mount up and go and freak some people out!

I hope you liked this instructable, please feel free to ask questions or suggest modifications.


shuberty (author)2009-11-03

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)shuberty2012-11-28

very late reply! a group of jellyfish is actually called a "smack" ... :)

Powerhouse (author)2008-02-06

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.

Tigerlilymama (author)Powerhouse2011-10-17

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?

Powerhouse (author)Tigerlilymama2011-10-17

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!

cchambers3 (author)2011-05-30

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! :)

maheesa (author)2010-10-14

For wiring the positive terminal, do you solder to the spring?

deadinsect (author)maheesa2010-10-15

I did, yeah

sewer72 (author)2008-10-22

I'm in a deep-water aerobics class. Would this work in a pool?

BuffaloNickel (author)sewer722009-10-29

like not at all, electricity+water=no!

ajam123 (author)2009-09-30

More like an instant seizure costume... ;P

ckdkjunk (author)2009-09-18

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)ckdkjunk2009-09-21

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

sibiria (author)2009-09-18

This is so awesome!!! If I am going to halloween party this is my costume :)

psycho.sloth (author)2009-06-11

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. :)

daphnegirl (author)2008-12-04

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)daphnegirl2008-12-05

thanks! pics with flash do look really stupid, I shold have warned people about that in the text! ant

jasmines (author)2008-11-11

This is awesome. I love it!

chakuseki (author)2008-11-03

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!

xand3r (author)2008-11-02
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??

gsurov (author)2008-10-28

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.

pedaleo (author)2007-10-17

Can you please help me with details on doing the electrical connections. I'm not very good at this...

deadinsect (author)pedaleo2007-10-17

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....!

crbnmnxide (author)deadinsect2007-10-18

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)crbnmnxide2007-10-18

I think you would get away with it for 6 hours or so?! ant

t_roy (author)deadinsect2008-10-26

Ok i hooded everything up right. But the batteries seem to get very hot.

Powerhouse (author)pedaleo2008-02-06

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.

miaou (author)2008-09-20

is the "connect all the LEDs together" step necessary, or could you just put batteries in each of the individual light strands?

deadinsect (author)miaou2008-09-22

you can do that. the strands all come with batteries. Each one lasts about one night - 6 hours?

miaou (author)deadinsect2008-09-22

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?

WonderWheeler (author)2008-09-22

I think women would look great in these too.

deadinsect (author)WonderWheeler2008-09-22

I was just at a music festival (bestival) in the UK, and loads of people had made these. chicks do look good in them.

deadinsect (author)2008-09-22

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.

pjak (author)2008-08-13

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)pjak2008-08-13

go for it. am going to rent or lend it someone though. more fish the merrier, ant

fernandonh (author)2008-05-16

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)fernandonh2008-05-25

my friends are going all the way to burning man from the UK - I'll tell them to look out for jellyfish!!!

fernandonh (author)deadinsect2008-05-26

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!

Shifrin (author)2008-01-05

Sweet, That is Awesome!

AngryPuppy (author)2007-10-31

Great tutorial, I'm just putting the finishing touches to my own jellyfish costume for tonight.

It was *IMPOSSIBLE* to find a round plastic wash basin / salad bowl in Belfast, I checked several pound shops and every store with a Home section I could think of. I bought some awful alternatives but luckily my mum is an artsy type and has reels of beer tubing lying around, so I've constructed a kind of dome skeleton out of that and it's going to be coverered with a white sheet.

Using more tubing cable tied to a helmet the whole thing is elevated above my head a bit, and I've filled the dome with five or so of the LED lights, comes through the white clothe really nicely. Can't wait to get out, I'll try and get some pictures but it'll have to be off a friends camera.

Didn't really have the time to do the wiring, and with the cloth jellyfish it might not have been as practical, but I ran one of the LED necklaces when they first arrived and it did indeed last a good six hours or so. Now if I can only stop playing with them before tonight they should last rightly.

Cheers again!

deadinsect (author)AngryPuppy2007-10-31

incredible - can't wait to see pics! ant

Kapitan (author)2007-10-29

I found that the button cells in the necklaces that I got were 1.6v each x 3 = 4.8v. This worked perfectly with the 4 x AA battery case with built-in power switch I found at RadioShack because I used NiMH rechargable AA's at 1.2v each (1.2 x 4 = 4.8v). The 4 AA's weren't too heavy mounted right on the helmet, but they didn't last very long. It was a good idea to have extra batteries with me.

Battery case I used: RadioShack

msmith9899 (author)2007-10-29

One of my friends was a jelly fish at a party the other night. Her costume wasn't nearly as cool as this, but she did carry around a few of those electric hand buzzers and "zapped" people when they came too near. It was funny!

Kapitan (author)2007-10-28

I made this costume and wore it to a party last night. It was a huge hit! Thanks.

deadinsect (author)Kapitan2007-10-28

oh my god really? well done! have you got pics!? anthony

Kapitan (author)deadinsect2007-10-28
Yeah but I think this costume is best shown on video. ;-)

keefurxxcore (author)2007-10-20

Can you tell me how to wire the "On/ off" selector please?

Also- Do I have to wire everything together?

guerroloco (author)2007-10-17

EL wire would make a good (& lighter) variation on this.

mattmill (author)2007-10-13

My son whats this so bad. I ordered the necklaces from SureGlowSureGlow they were $1.50+s/h. Now off to find a bowl big enough :)


About This Instructable




Bio: I am interested in the boundaries between engineering and art, with a slightly eco/nature vibe.
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