Sep 3, 2019

Alien Cosplay 3.0 - Build Log

I have created a new Alien "Big Chap" costume to wear at 2019 Dragon Con!

The entire build has taken several years due to life events hijacking my project, however after months of hard work and plenty of failures, I finally have completed my animatronic Alien costume. This is the 3rd alien costume build, and the first "real" cosplay I have attempted to solo build after learning more about cosplay fabrication methods from my friends and peers.

This costume was built upon the amazing Pilerud Cosplay's RPF progress photos, which were made freely available back in 2017. While he does not include a "how-to" or step-by-step for his costume, he has plenty of WIP pics and videos that show the components broken down to their basic parts. He was also very open to answering my questions when I reached out to him online.

His patterns helped me realize just how I can shape and form EVA to create complex organic props and armor. But while the basis of my alien was built upon his plans, I did several things differently, including re-shaping the tail, changing the chest and ribs connections (which need another revamp), overhauling the patterns for the dorsal pipes to include a bend, and using epoxy resin vs. polyester resin + woodglue to coat the props. A lot of this build was also trial and error in figuring out what would work best for ME based on the materials I had access to, and my own understanding of manipulating them.

Cat nephew Calcifer providing moral support

I cannot thank the support of my friends at Overworld Designs and MakingItUp enough, they were very supportive of me and this build over the years and I would have never known where to start had it not been for them introducing me to all of the different materials that I have used in this costume! They also only made fun of me a few times for working on alien costumes for 5 years!

And finally, I want to thank my amazing mom for being awesome and helping her adult daughter sew her weird monster costume's neck piece, hands, gloves, and nylon connections. I also want to thank my dad for giving me an extra hand in mixing the plaster for the dome mold and for assisting me in dumping gallons of boiling water into a giant dye tub, and not really questioning it.


How long did this build take?
I started this project years ago, however scrapped a failed build as I was learning materials the hard way as I went. Due to infrequent opportunities to work on the project, life events, and my own laziness, this took me about 3 years to complete. You can build this in less than 1.

How much did this costume cost?
For my own sanity's sake I have stopped keeping track. The epoxy coating, the PETG domes, and the EVA and pink foam were the main components of the costume that took a lot of money upfront, however all of the tools, glue, paint, and smaller components added up quickly overtime.

I would estimate over a couple of grand was spent, however this was due to my own inexperience working with certain materials and scrapping a previous build. You can do this cheaper if you know exactly what you're doing and if you have access to many of the necessary tools already.

How did you make the clear dome!?
The dome was vacuum formed out of clear 0.08" PETG plastic on a large-format vacuum former machine run by the amazing folks at Studio Creations. They were enormously helpful in guiding me towards creating the proper buck for my build and I could not have achieved the clarity on the dome that I did without their advice. The buck is a huge (and heavy!) plaster cast that was coated in EpoxAmite and sanded and buffed to a glass-smooth finish. You can see the forming in action here!

The plaster + EpoxAmite buck ready for vacuum forming.

Can you see?
Yes, but not easily. I can see out of the skull eyes, and down through the bottom of the jaw. I need a handler for this costume, especially since it is warm, I'm wearing heels, and my head/chest/tail stick out from behind me and take up extra space. I have no peripheral vision.

Can you breathe?
Yes, I have small hidden slots along the sides of my costume where my face is that allow for more ventilation in my helmet, and there is ventilation under and through the jaw!

Is the tail permanently attached?
No, the tail can be disconnected separately to a mount plate under the suit for easier storage. My cosplay can be broken up into the following individual pieces: head, neck cover, chest, dorsal pipes, suit, gloves, glove cuffs, tail, and shoes.

Can I buy the costume/are you taking commissions for this costume?
No, but I would be happy to share my experiences with building this costume and would be more than happy to answer your questions. I do not do any cosplay commissions since this is just a side hobby for me.

Have you done other cosplays?
Yes and no. This is my 3rd cosplay, however this is my first "real" solo build after doing work with my cosplay friends and absorbing a lot of knowledge from them. My last 2 cosplays were also aliens... I just really wanted to get a version with animatronics working. I'm ready to do something else!

Materials Used:

The base components for sculpting and building the costume pieces.

Head Base
- Pink insulation foam board (2" thick)
     - Base form
- EVA foam (12mm)
- Worbla's Black Art
     - Skull face, extra support in roof of helmet
- Bondo spot putty
     - Blend clear dome into the helmet
- Friendly Plastic modeling pellet
     - Various sculpting on head, blending tubes into helmet
- Plastic siphon pump
- Flexible radiator hose
- Plastic clothes hanger
- Split loom tubing
- Black stocking
     - Sheer under the jaw so I could see out through it
- Resin
     - Cast teeth
- Helmet padding

Jaw/Tongue Mechanism
- Bicycle brake cable
- Hi-Torque Servo
- Extra-long servo horn
- EZ Servo Horn Connector
     - For pushrod connection to bike cable
- Servo Tester (HobbyKing LED Servo Tester)
     - Controller for sweeping the servo
- Wire (electronics)
- Limit switches
- 6v NiMH Battery Pack
     - Battery case lock
- 3D printed tongue, switch, and gliding mounts
- Acrylic sheet
     -  Servo and mechanism mounting plate
- 3D printed battery case
- Parachute buckle
     - Battery case lock
- Ribbon
     - Battery case so I could easily remove it
- Elastic strap
     - For battery case buckle
- EVA foam (2mm)
     - Battery case lining
- Large vacuum tube
     - Base of tongue
- Foam clay
     - Sculpting on tongue base, teeth
- Split loom tubing
- Neodymium magnets
     -  Mount tongue sheath to mechanism
- Wire clothes hanger
- Aluminum armature wire
- Worbla's Black Art
     - Chin mount
- Elastic strap
     - Jaw spring-back and chin mount for controlling jaw puppet
- Hardware (screws/locknuts/washers)
     - Jaw hinge movement

Dome (link to forming video!)
- PETG 0.08" Clear
- Plaster
     - Vacuum forming buck
- EpoxAmite
     - Vacuum forming buck top layer
- iDye Poly Black
- iDye Poly Brown (equal parts colors for dying)

Calcifer inspecting the dome. He's not afraid of no Alien!

Neck Cover
- Balaclava
     -Separate piece underneath that keeps hair down and protects inside helmet from dripping sweat
- 4-way stretch fabric
- Pellon Flex Foam
     -  For ribbing detail
- Split loom tubing
- EVA foam (12mm)
- Zipper 
- Velcro
- Wire clothes hanger

- EVA foam (12mm)
- EVA foam (6mm)
- Split loom tubing
- Neodymium magnets
     - For connect ribs to back when it's on. WILL BE REPLACING THIS SYSTEM! Doesn't work well.
- Aluminum armature wire
- Hardware (washers)
     - For mounting removeable dorsal pipes to back of costume

Armature wire was hot glued to the back of the ribs to provide support.

Dorsal Pipes
- EVA foam (6mm)
- Split loom tubing
- Foam clay
     - Gap fill
- Hardware (screws, wingnuts)
     - For mounting removeable pipes to back of chest piece

EVA foam (12mm)
- EVA foam (2mm)
- Foam pipe insulation
     - Base of tail
- Large armature wire
     - Tail core
- Aluminum sheet
     - Hammered into shape as tail mount base
- Parachute buckles
     - 2" buckle for connecting tail to mounting plate
     -1.5" buckle for mounting plate waist strap
- Center button buckles
     - Extra buckles to wrap from under and around legs for extra support to mounting plate
- 3D printed buckle mount
     - Attach 2" parachute buckle to armature wire
- Hardware (pop rivets, screws, washers, lock nuts)
     - Mounting parachute buckles to plate and wire
- Nylon straps
- Elastic straps
- Leather rivet

- Black, non-zipper boot with heel
- EVA foam (12mm)
      -For filling in gap between shoe sole and heel
- Worbla's Black Art
- Foam clay
- 4-way stretch fabric
- Split loom tubing
- Fake nails
- Smooth-On Free Form SCULPT
     - For filling in and repairing heel after sanding it down into shape

- 4-way stretch fabric
- EVA foam (12mm)
     -  Fake finger stuffing and elongating fingers
- Split loom tubing
- Pellon Flex Foam
     - Cuff stuffing
- Hook and eyes
- Velcro
- Fake nails

- Black morph suit
- Acetone
     - Remove morph suit brand lettering
- Split loom tubing
- Worbla's Black Art
     - Inner muscle sculpts
- Foam clay
- EVA foam (12mm)
- EVA foam (6mm)
- EVA foam (2mm)
- Elastic cord
- Black plastic HDPE tubing
- Velcro

Glues and Paints:

Many different types of adhesives, coatings, and paints were used in this build. I recommend testing a small amount of any product on a scrap piece of material before you fully apply it!

- Black hot glue sticks (best for any time I needed fast drying)
     - EVA to fabric/suit
     - Fabric to Worbla
     - Worbla to Worbla
     - Nylon strap to nylon strap (after sewing, for extra strength)
     - Split loom tubing to anything
     - Elastic cord to fabric/suit
     - Small detail EVA to EVA when I needed fast drying
     - Armature wire to EVA
     - Helmet details to helmet base AFTER coated with Epsilon Pro
     - Foam head padding to helmet base AFTER coated with Epsilon Pro
- Super glue/cyanoacrylate (liquid)
     - Large piece EVA to EVA (I am beginning to prefer hot-gluing all of my EVA however)
     - Small EVA to foam insulation pipe tail (hot glue would melt insulation pipe and add too much weight)
- Super glue/cyanoacrylate (gel)
     - Neodymium magnets to EVA
- E6000 black
     - Nylon elastic to nylon elastic (extra flexible support after sewing)
- Great Stuff foam sealant
      - Pink insulation foam to pink insulation foam
- 2-part epoxy
     - Extra strength added to 3D printed jaw mechanism connections and mild gap fill
- 2-part steel epoxy
     - Extra EXTRA strength added to jaw mechanism brake cable connections and mounts so parts would not shift
- Smooth-On Free Form SCULPT
     - Filling in and reshaping shoe heels
     - Fixing potholes in plaster dome buck
     - Add rigidity and mass to tail parachute buckle connections

- Epsilon Pro
     - Coat pink foam/EVA foam/foam clay
     - Can be sanded, but apply in multiple thin layers for best smooth application
- EpoxAmite
     -  Coat plaster dome vacuum forming buck for smoother finish that can be sanded and buffed

- Auto primer (spraycan)
- Krylon Fusion matte black (spraycan)
- Krylon Fusion satin dover white (spraycan)
     -Skull base
- Rust-Oleam metallic silver (spraycan)
     - Teeth
- Tamiya matte black (airbrush)
- Tamiya matte brown (airbrush)
- Tamiya metallic grey (airbrush)
- Acrylic black (tube)
     - Touch-ups and fixes 
     - Skull and tongue detailing
- Acrylic burnt umber (tube)
     - Skull and tongue detailing
- Acrylic metallic silver (tube)
     - Inner tongue teeth
- Krylon clear coat matte UV (spraycan)
- Krylon clear coat satin (spraycan)
- Krylon clear coat gloss UV (spraycan)


I used a huge variety of tools to make this costume happen. While not all of these are necessary, some of them certainly made the job much easier for me for the methods I used. I won't list off every tool that I touched for this project, but some of the more notable ones are:

Hot Wire Foam Sculpting Tool
- Basic block sculpting of the head

- I carved the majority of the head base with this when I needed more control, as the hot wire cutter could very easily cut away more than needed

Power Drill Large Sanding Drum Bit
- For smoothening out and sculpting the pink foam head base

Large sanding drums for a hand drill were used for sanding the pink foam base sculpt

Rotary Tool/Dremel
- Sanding bit for majority of small EVA foam sculpting
- Tons of other bits for various sculpting or drilling work

Leather Double Cap Rivet Tool
For mounting the leg support tail straps to the aluminum plate (allowed the straps to pivot)

Large Rubber Mallet
- For hammering the aluminum butt plate/tail mount into shape
- For hammering the double cap rivet into the aluminum plate for the extra leg support straps

Belt Sander
- Cheap Harbor Freight sander for large EVA piece sculpting and smoothing the teeth sculpts

Sewing Machine
- Stretch needles for the 4-way stretch fabric
- Heavy duty needles for nylon strapping

Giant Plastic Tubs
- For plaster mold pouring using my cheap risky method
- For dunking PETG domes into dye bath

Duct Tape Dummy
- For modeling the morph suit as I glued details to it

A duct tape dummy or dress form is invaluable in making sure your patterns are correctly sized and shaped.


My main reasoning for revisiting the Alien again for a cosplay was to finally accomplish the moving jaw mechanism. The only electronic components to the head involve moving the tongue; the outer main jaw is puppeteered by my own jaw. This means that when I open my mouth, the chin elastic straps pull down on a wire that pull down on the prop jaw. A smaller elastic strap under tension pulls the jaw back closed. This means that the head is NOT actually supported by my chinstrap, but completely by tension against my forehead with helmet padding! Without enough padding to support the head, the jaw strap cannot work.

Animatronic tongue schematics. The push buttons were replaced with limit switches for ease of use.

When the mouth is open, it triggers a limit switch to turn on power to the tongue mechanism. Once that is on, I can press another limit switch with my tongue to make the alien tongue move. The first switch prevents the battery from running constantly and saves me power at the convention. Pressing the second button moves a servo in the back of my head that pushes a brake cable all the way towards my front and pushes out the tongue sleeve over a tube. Pressing the button with my tongue frees up my hands from having to operate the animatronic and it also makes for a fun story when explaining it to people.

Not included in this video is the E-Z Connector that I eventually used to connect the brake cable to the servo horn.
Without this connector, the wire would get caught on the horn after some time.

My original plans for the tongue were to be powered by an Arduino, however even the small micro-controller was more than needed for a simple servo sweep motion. I moved away from the Arduino design after consulting with Pilerud Cosplay on his own mechanism design that used the servo tester instead. I feel that with a simpler controller, the build is more solid and I do not have to deal with the servo jitter caused by the Arduino.

For more schematics and photos of the jaw mechanism, check out my download link at the top of the post!


I store my entire costume in a large rolling toolbox. I decked it out with a few custom laser-engraved aluminum data plates, and a spray-painted logo. I highly recommend the rigid toolboxes for storing your costumes all in one place! They are available in different sizes depending on your needs, and the hardshell frame is perfect for protecting your cosplay during storage and transport.

If you took a pic with me please send me a note I'd love to see it! And stay tuned here or at my Facebook or Instagram for more details on this build and future builds! Thanks!