Halloween Underwater Theme - How to Make a Kraken

This year I brought the Kraken to life in our epic underwater theme! Oh, it was a real fun with hundreds of little “monsters” visiting our house.

Let this inspire you and if you’re up for the challenge (and fun) next year, I hope this guide will be your treasure map to a great Halloween display.

Let’s be honest: Pinterest gave me a lot of ideas for glamorous, tropical vibes, but I wanted something a bit more… spine-tingling.

Grab your diving gear and get ready to unleash the Kraken in all its terrifying glory.

Let’s dive into the details!

And you can make your car looking like mine with another instructable here: https://www.instructables.com/How-to-Create-a-Rusty-Looking-Car-for-an-Underwate/

Materials You’ll Need to Summon the Kraken:

Base (Bottom Part): A large plastic bowl makes the perfect sturdy base.

Middle Section: Any box will do! I used a Styrofoam insert from a freezer box (picked up for cheap and previously transformed into a witch's cauldron, which is why it's black). It’s lightweight and easy to work with!

Kraken Head: A yoga ball works best—super versatile and reusable for all kinds of holiday decorations, from spooky Halloween to festive Christmas.

Foamboard or cardboard: for the eyes, to cut the shape,

Plastic or acrylic sheet: for diffusing the light to create eerie, otherworldly eyes

Expandable Foam (PE Foam): Go for the cheapest option; you’re not building a house here! This foam gives the Kraken its monstrous shape and texture.

Lighting: Any light source works, as long as it shines through the eyes. I used a spare Ikea lamp, but feel free to get creative with what you have on hand.

Aluminum Foil: Great for creating structure and texture. For creating suckers and forming pointy ends of the arms.

Plastic Wrapping Foil: Ideal for layering, adding durability and skin-like texture

Masking Tape: For holding things in place while you work your magic.

Flexible Aluminum AC Ducts (4-inch, 6-inch, and 8-inch) – for making the Kraken’s arms. (Affordable options work fine; they often come with gloves and clamps).

Weights or containers filled with sand – to secure the arms to the ground.

Wire or zip ties – to attach the arms to a car or secure them in place.

Paper Sheets

Paints:

1. Black Spray Paint – for the base color.
2. Green Spray Paint – for the opposite side of the arms.
3. Brown Spray Paint – to blend the colors.
4. Light Green Paint – for highlighting the suckers.

Tools

1. Heat Gun or Hairdryer – for setting the plastic wrap on the arms.
2. Glue Gun – for attaching suckers and securing other components.
3. Masking Tape – for securing and wrapping parts.
4. Gloves – recommended for working with sharp wires and ducts (often included with duct kits).

Let the Kraken-crafting begin! Start by putting all the elements together like a mad scientist piecing together a sea monster. Secure them with tape—duct tape works, but I found that switching to masking tape made things way easier (and cheaper!).

Now for the fun part: shaping the Kraken! Use aluminum foil, masking tape, and plastic wrap to mold and twist until you’ve got a head shape that says, “I’m the terror of the seas!”

Once you’ve got your base shape looking nice and monstrous, it’s time to bring the Kraken to life with some light. I didn’t exactly have a master plan here, but it worked out perfectly—I could focus on the shape without wrestling with the light at the same time.

It’s time to give your Kraken that piercing, deep-sea stare! Grab a piece of foam board and sketch out the shape of the eyes—don’t stress about perfection; this is Kraken crafting, not surgery! Just go for a spooky vibe. Hold the foam board up to the head to find the perfect spot for those eyes and mark out where you’ll add the PE foam lines for a creepy, textured look.

Start by cutting a small hole in the middle of the head to mark the spot where the light will be installed. This is where the magic will happen, illuminating your Kraken’s gaze with an eerie glow!

Finally, cut a larger opening in the head where you’ll install the light, which will later be covered by the Kraken’s eyes.

One pro tip: make sure the switch is accessible from the outside. The Kraken doesn’t need to terrorize the seas (or your yard) in daylight!

Once you’re happy with the eye positions, do a test run. Flick on the light to make sure it’s casting just the right amount of eerie glow. Adjust as needed until you get that “stare of death” effect.

Now, for the finishing touch on the eyes: add a double layer of acrylic sheet, with a thin paper sheet in between to diffuse the light and hide the bulb. Secure everything with your trusty glue gun and some masking tape. And voilà! Your Kraken is ready to strike fear with its haunting, glowing gaze.

Now comes the really fun part—adding that gnarly, monstrous texture with PE foam! Fill the gaps between the Kraken’s head and eyes to give it that full, fleshy look. Then, go wild creating lines and ridges on the head to give it some serious sea-beast vibes.

Remember, this isn’t a cute, cuddly creature; it’s a Kraken! So let your creativity flow, and don’t hold back. PE foam is forgiving and flexible, so get creative with all those gnarly, twisted details. The more monstrous, the better!

Once you’re satisfied with all the monstrous details and gnarly textures, step back and admire your work—it’s time to give your Kraken a break! Set the body aside and let the foam dry completely. This usually takes a few hours, but for best results, leave it overnight.

With a bit of patience, your Kraken will be ready for the final touches soon!

You can start working on Kraken's arms. You will find the instructions in step 5..

Time to bring your Kraken to life with a dark, ominous coat of paint! Start by covering the eyes with masking tape so they stay nice and transparent.

Grab any spray paint you have on hand—I used a black glossy spray, which added a great deep-sea shine to the beast. After the first coat, wait a bit and turn on the light to check how the paint job looks in action. You might notice some areas where the light shines through a bit too much. If that’s not the look you’re going for, simply add another coat to cover any see-through spots.

Once you’re satisfied with the coverage, let it dry, and your Kraken is almost ready to haunt the seas!

With the head ready to terrify, it’s time to give your Kraken some powerful tentacles!

1. Stretch the Ducts: Grab each duct, which likely has sharp wire ends, so wearing gloves might be a good idea. Stretch them out to get that long, sinewy look for each arm.
2. Wrap with Masking Tape: Wrap each duct with masking tape to smooth out the surface. A little tip from my own experience—wrapping the entire length first and cutting it later is much easier than dealing with shorter pieces. I worked alone so I anchored one end of the duct with a hanger and hooked it onto a door handle to keep it stretched. Find what works for you and go for it!
3. Add Skin Texture with Plastic Wrap: To give the arms a realistic “skin” texture, wrap each piece with plastic wrap. I used packing wrap for extra durability and stretch. Don’t worry if it doesn’t stick perfectly; you can fix that up with a heating gun or hairdryer.

Now you’ve got a Kraken with some serious arms ready to reach out from the deep!

I completely forgot about this step, so here you can see that I first added suckers and then the pointed ends. For obvious reasons, it's easier to do it in a correct order :-)

1. Extension with Paper Rolls: Roll up two sheets of paper to extend the arm. This adds a bit of length and allows you to shape the ends.
2. Cover with Aluminum Foil: Wrap a thick layer of aluminum foil around the paper extension. Squash the end into a sharp, pointy shape for that menacing look.
3. Wrap with Masking Tape: Secure everything with masking tape to keep it sturdy.
4. Final Layer with Plastic Wrap: Cover the whole thing in a stretchy plastic wrap to give it a smooth, “skin-like” finish.

Side Note: Initially, I considered joining different sized ducts to create one long arm, but it turned out trickier than expected. So instead, I made the arms look like they were diving in and out of the ground—a spooky effect that turned out even better!

1. Create Suckers with Aluminum Foil: Cut aluminum foil into small pieces and roll each piece into a thin rope. Then, shape each one into a little circle to form a sucker. Easy peasy. No need to overthink it.
2. Attach to the Arms: Using a glue gun, fix the suckers onto each arm. For the thinner arms, one row of suckers works great. For the medium and larger arms, go for two rows to make them look extra intimidating!

This detail adds the perfect Kraken vibe, bringing your sea monster to life with those unmistakable, creepy tentacles! Ready for the final steps?

Now it’s time to add some color to those terrifying tentacles!

1. Base Colors: Start by painting one side of each arm black along the full length. Then, paint the opposite side with green. This two-tone effect adds depth and a sense of eerie realism.
2. Blending with Brown: Use brown paint to blend the joint where the black and green meet. This gives the arms a natural, creepy transition between colors.
3. Detailing the Suckers: Add lighter shades of green to the suckers, making them pop and giving that extra dimension to the texture.

This painting process is quick, easy, and a whole lot of fun! Now your Kraken has vibrant, lifelike arms ready to stretch out into the night.

It’s time to bring all the Kraken parts together and unleash your creation!

1. Secure the Arms: Place heavy weights or yogurt containers filled with sand at each end of the Kraken’s arms to anchor them securely to the ground. This setup is sturdy enough to handle a swarm of curious kids, so no need to overthink it!
2. Position and Wrap: Arrange the arms as if they’re emerging from the depths, stretching across the ground, or wrapping around objects. For an extra dramatic effect, wrap a few arms around your car (if you’ve painted it Kraken-themed, even better!).- I have created another instructable on how to create the underwater rusty car effect. You can find it here: https://www.instructables.com/How-to-Create-a-Rusty-Looking-Car-for-an-Underwate/
3. Final Adjustments: Make sure everything is positioned securely and that the suckers and textures are visible for maximum effect. You’re ready to unveil your sea monster!

Now you have a Kraken display that's sure to be the talk of Halloween! 🎃