The giant sandworms of Dune can grow to over 400 meters long, and are equipped with an incredible array of crystalline teeth. They dwell in the deep desert on the planet Arrakis, sole source of the prescience-inducing spice drug melange, and are known to native Fremen as Shai-Hulud. The worms create the spice, and he who controls the spice controls the universe.

If you wish to follow in Leto II's footsteps and transform yourself into a living embodiment of Shai-Hulud, simply follow this Instructable.

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I got one of these cheap play tunnels for my kids, and suddenly had an epiphany: it would make an awesome base for a Shai-Hulud costume. As a long-time Dune fan and all-around geek, dressing up as a giant sandworm was quite possibly the best. Thing. Ever.

A google image search turned up just one previous attempt, a two-person affair which looked more like a Chinese dragon costume, so this obviously had to be made. Eric and I both worked on this costume, and I wore it during the day to our company Halloween party (where it won Scariest Costume!) and he wore it while out trick-or-treating with our daughter, who dressed up as Alia. (See Step 8.)

It turns out to be an excellent geek test: do people think you're a Sarlaac? From Tremors? If they know you're from Dune, do they think of the books, David Lynch movie, or SciFi Channel mini-series? (For the record, it's the Frank Herbert books all the way, with the movie for classic campy fun.)

The costume was actually pretty simple to make, once we got the concept down. It takes a while to assemble all the parts, but the end result is a ridiculously sturdy costume that will stand up to abuse from adults, kids, and very confused pets. I'm hanging it up in my office, and will add pictures once it's properly rigged.

Intro image is a composite made with Pixlr Editor. Background photo is of the Peruvian desert outside Huacachina. Blue eyes throughout also courtesy of Pixlr.

Step 1: Tools and Materials

Materials for sandworm:
1 children's play tunnel. I bought this one from Amazon for ~$13.
6 yards 60" wide, heavy sand-colored fabric for the skin (adjust to size of tunnel)
1 yard pinkish fabric for the mouth
1 sheet thin white posterboard
2 yards coated wire
large cardboard box

Materials for Fremen costume:
black wetsuit or similarly body-hugging clothing
black cape (or material for a cape)
paracord
large metal hooks (or cardboard and aluminum foil)

Tools:
sewing machine
serger (optional)
sewing awl
hot glue gun
laser cutter or X-acto knife
scissors or rotary cutter
long straight edge
fabric marker (optional)
measuring tape

Step 2: Cut and Sew Sandworm Skin

A sandworm's skin is made of a series of overlapping rings that clamp tightly shut to keep the sand out. The rings openings face the sandworm's tail, so it doesn't pick up sand as it glides along through the dunes.

Measure your tube's circumference, and be sure to buy fabric wide enough to fit around it in one go. That probably means a ~60" wide bolt of fabric. Since my material had a shiny side (the inside - sandworm skin isn't shiny!) and a matte side (external-facing for better sandworm skin) I'll be using the terms shiny and matte below to indicate how to position your fabric. Though the description below is hard to follow, the actual placement is pretty simple - just mess with it (use strips of paper and tape if you need to) until you understand what's going on.

Cut a series of 12" x 60" strips from your sand-colored fabric. I required 13 strips to create a cover for my sandworm's body tube.

Serge both cut edges of each strip, then fold under and hem one side of each strip. Remember the matte side faces out, so be sure to fold/hem appropriately.

Fold one strip in half long-ways, shiny-side out, and place on top of a matte-side-up piece. Place the folded edge up against one of the serged edges, and sew the two pieces together as shown in picture 4 above.

Unfold, and the top side of the previously-folded piece (the side NOT overlapping the first strip) becomes your new bottom strip.

Repeat the layers until you've got enough length to cover your entire tube, with a few inches to spare for overlap.

Step 3: Pin and Sew to Tube

This is the real fiddly bit.

The first time through, we pinned all the way along the body, then Eric gave it a quick seam. This sucked for several reasons: first, the pinning wasn't even because he'd matched the (compressible) tube, and second, the flaps didn't lay flat across the seam. I ended up going OCD and ripping the seam out, repinning, and re-sewing.

The second time, I placed one pin at the end of the tube to mark the circumference, then took the skin off and laid it flat on the floor (inside out so you get the seam on the proper side!) for further pinning. I carefully matched up each flap and seam so the sandworm's body would be even (there were LOTS of pins!) and kept a constant diameter all the way down the tube.

Sewing was pretty easy, though you've got to go slowly to remove all of those pins. It worked out pretty nicely.

Now flip the worm skin right-side out, and scoot it onto the tube. If it doesn't fit, curse heavily and re-do. Once it fits, curve the top of your fabric (remember, the sandworm's segments open towards the back) over the top edge of the tube, and pin it in place below the metal wire. Sew around the top of the tube. You should be sewing through 3 layers (fabric, tube, fabric) and avoiding the metal wire at the top, and the bit of metal wire spiraling down the tube.

Step 4: Make Mouth

A sandworm has a tripartite mouth, which I've created with cloth-covered cardboard.

I wanted it to be flexible, and had visions of actuating it with little dowels. That didn't prove reasonable, due to the presence of sharp teeth (ouch!) and logistics of wearing/carrying the costume around. The mouth still waggled a bit as I moved, which was sufficiently creepy.

Cut three curved triangles to serve as the mouth. I used the highly technical "guess and check" method here - YMMV. Be sure that the corrugations run in the proper direction so you can curl the cardboard up to fit the tube. Fold in half to ensure your mouth-parts are symmetrical, and trace to ensure they're all the same. Give them another good curling/folding to make sure they're nice and bendy.

Cut a piece of each fabric (pink and sand-colored) to match the mouth parts, with about a 1/2"-1" seam allowance on all sides. (Note that the seam on my sand-colored fabric wasn't an aesthetic choice - I had simply converted all of the fabric to 12" strips, and had to combine to fit.) Serge edges to prevent raveling.

Sew the curved edges together, right-sides in, then flip right-side-out and insert the cardboard.

Attach cloth to the surface of the cardboard with hot glue, then fold under the bottom edges and hot-glue shut like you're wrapping a present. Don't these look awesome?

Step 5: Attach Mouth

Attach mouth parts to the body of your worm.

I used an awl to make holes in the fabric and cardboard, and looped wire through the cardboard, under the wire edge of the tube, and back at about 2" intervals. (see 2nd picture) Tie off at the end of each mouth flap, and keep all the ends inside the tube so it looks tidy.

Be sure to space your mouth flaps evenly around the tube! Sandworms don't have mouth gaps.

You'll note I experimented with teeth before attaching the mouth parts - don't do this. It's much easier to attach teeth AFTER you sew the mouth onto your worm.

Now is also a good time to give your sandworm internal handles so you can properly menace people from within. I used paracord, and simply tied it into the wires holding the mouth together. You don't want much slack in the cord, just enough to slip your hands through.

Step 6: Cut Teeth

Cut a bunch of sandworm teeth. I've attached the file so you can laser-cut them (fast! highly recommended if you can access a laser cutter!) and the picture they're based on.

Teeth are the make-or-break part of this costume. You really need a large number of realistically-shaped teeth to pull off the proper sandworm effect.

While I wish we could have 3D printed teeth so they could be properly crystalline, they'd be crazy expensive and hard to attach to the mouth parts. If you have access to a 3D printer, print one to make yourself a crysknife. Polish the resin for best effect.

Step 7: Attach Teeth

The teeth are easily attached with hot glue. The hard part is getting the fold right so they sit properly within the sandworm's mouth.

Note that the teeth need to curve inward to prevent prey from escaping*, and need to stick up enough to look threatening but not at 90 degrees or you'll poke your eyes out. (The posterboard is pretty sharp.) You'll waste a few teeth getting the exact fold right, but once you've got a model it's easy to replicate.

Stagger teeth in rows, and use as many as you realistically can.

I considered attaching additional teeth to a crown/headband atop my head, as sandworm teeth just keep going, but we ran out of time. Filed for later.

*Successfully tested by both a toddler and a cat! Each one crawled in, got stuck on the teeth when trying to get out, and yowled until extracted by an adult.

Step 8: Create Fremen Minions

Black wetsuits look enough like stillsuits to pass unless you're doing serious cosplay. Note that many colorful wetsuits are all-black on the inside - just turn them inside out. Equip your fremen with a crysknife, maker hooks attached to paracord, and maybe a thumper. A bit of black wire run from the ear to the nose makes it clear you're serious about reclaiming moisture.

If possible, add a jubba cloak. I made black cloaks for my kids the easy way. Measure shoulder-to-floor distance (drop) and shoulder width. Cut a rectangle of fabric to 1x drop by 2-3x shoulder width, depending on how swirly you want the cape. Measure head length (forehead to crown) and height (neck/shoulder join to top of head), and cut another rectangle that's 1.5x length x 2.5x height. Fold it in half, and sew a smooth curve for the back of the head. (Best to have the target head around to test against for this step.) Sew a running stitch along the neckline of the cloak and the hood, gather to the same length, then sew them together. Cover and reinforce the join with another strip of black cloth.

We dressed my 4-year-old daughter as Alia, so I folded over the front edge of the hood and ran a piece of black yarn through so we could pull the hood tight around her face. We watched the David Lynch version of Dune before Halloween, so she was fully primed to be super-creepy. As I write this up, she's asking "where's my crysknife? And when do I get a gom jabbar?"

Geek parenting win. :)

Step 9: Go Forth

Gather your army of Fremen, strap on your crysknife, and wear the skin of Shai-Hulud with desert pride.

Bless the Maker and all His Water. Bless the coming and going of Him, May His passing cleanse the world. May He keep the world for his people.
- Fremen saying

Do fun things with your sandworm. Crouch down to compress the tube, then launch yourself at unsuspecting passers-by and attempt to eat their heads. It's quite fulfilling. Since the body is fully compressible, you can carry the sandworm around on your arm, or tie it up and wear it on your back. Hang it from a (high) ceiling to menace your office mates.

Caution: some find Shai-Hulud to be adorable, and may attack your sandworm with hugs. Eat them preemptively.