Introduction: 100% Edible Aliens Inspired Chestburster Gelatin Babycake

About: Hands-on DIY lover and borderline crazy crafter. I love Halloween and creepy food.

A few months ago deep down a rabbit hole of weirdness on Pinterest, I came across a gelatin cake specifically made for baby showers. It was a pregnant woman with a tiny baby in her stomach, visible through the clear gelatin.

While creeped out, I was also intrigued and knew I wanted to make my own version of this...but with a bit of a twist. I knew putting a baby inside the belly of this mold was way too…normal. And being a fan of the franchise Aliens, the leap to chestburster was almost instantaneous.

I mean, who could forget that epic moment in Aliens 3 when Ripley finds out she’s actually carrying one inside her?

So inspired, I decided in that instant that not only did I have to make a chestburster babycake, but that I wanted to recreate the scene with Ripley.

To make your own Aliens inspired Chestburster Babycake you will need:


  • Cooking spray
  • 10 cups water, divided
  • ¼ cup mini marshmallows
  • 17 packages (17 Tablespoons) gelatin powder, divided
  • Yellow food coloring gel
  • Brown food coloring gel
  • Vodka
  • 5 cups sugar, divided
  • 2 1/2 teaspoons citric acid, divided
  • Pineapple flavored oil (I used Lorann)
  • ½ cup sweetened condensed milk
  • Green food coloring
  • Red food coloring
  • Chestburster embryo mold
  • Pregnant Woman Gelatin Mold

Step 1: Finding the Mother Mold

It was fairly easy to find the mold for the pregnant woman part of the project. Just google "Pregnant Woman Gelatin Mold" and several options pop up. I grabbed one for $12.

Step 2: DIY Your Own Chestburster Mold

Next I needed my chestburster. Molds for these are a lot harder to come by (haven't seen one yet) so I knew I was going to have to make my own.

A little digging online and I found the perfect 3-d file on Thingverse. Then it was a simple matter of downloading the file and printing it.

Don't have a 3-D printer? That's ok! You can find lots of amazing people online who are willing to print things and ship them to you for a relatively low cost.

Because my Alien printed on a base, I needed to remove it before I molded it. I used my Dremel and made quick work of the plastic base. This left me with a fairly rough looking Alien bottom.

I patched it up using Sculpy clay. To harden the clay, I hit it with my heat gun (carefully – you don’t want to melt your Alien!) going over it in short fast passes until the clay was no longer soft to the touch.

I sealed the entire thing with several coats of clear acrylic spray finish and prepared to mold it using Smooth-Sil 940 food safe silicone (you can pick it up on

I have a full tutorial up already on how to use the silicone here, so I’m not going to go into all of it again. Check that out if you’d like to make your own silicone molds.

With both molds now in hand, it was time to start making my Aliens inspired Ripley chestburster baby cake!

Step 3: So Sweet They'll Make Your Teeth Hurt

We’ll start by first making our chestbursters as they will need a bit of time to “cure.”

In a microwave safe bowl, sprinkle two packages of gelatin powder over the top of 1/2 cup cold water and allow to bloom for 10 minutes.

Once your gelatin has bloomed, pop the entire thing into the microwave for 60 seconds. Remove your gelatin from the microwave and give it a good stir.

It should be close to all melted and integrated into the water.

Add in your ¼ cup mini marshmallows and stir. The heat from the melted gelatin should start melting them as well.

Pop the entire bowl back into the microwave for another 30 seconds to ensure that all your gelatin and your marshmallows are fully melted and well combined.

Prep your chestburster mold by giving it a light spritz of cooking spray. Use a food safe paintbrush or a wadded up bit of paper towel to help ensure that you get spray into all the nooks and crannies. Wipe out any excess.

Carefully pour your marshmallow mixture into your chestburster mold and pop into the fridge for about 20 minutes. It should firm up and feel spongy yet not sticky to the touch.

Carefully remove your chestburster from your mold. You should have enough marshmallow sauce to make at least three chestbursters. While you only need 1 for the recipe, I made additional ones to practice my painting on…and to just eat because…marshmallows.

Step 4: Is It Just Me or Do They Look a Little Bit Like Banana Slugs at This Stage?

When you’ve finished molding your marshmallow chestbursters, it’s time to move onto giving them a bit of color. I did this using yellow and brown food coloring gel and a bit of vodka. The vodka is used to thin down the color so it's not quite so bright and gives the chestburster a nice muted shade.

In addition, the vodka evaporates quickly, helping to prevent your marshmallow from getting too soggy or melting. Don't use water, you'll just end up with a sticky gooey mess.

Once you’re done painting them, pop them into the fridge uncovered for about 4-6 hours. The dry air of the fridge will help make sure that the food coloring you used on them is really adhered to the marshmallow and will help prevent color bleed when you embed them in the gelatin later.

If you plan on making them ahead of time, pop a little plastic wrap over them after the 6 hours to keep them from drying out too much!

Step 5: Gettin' Jiggly With It

To make our pregnant gelatin stomach for our chestburster to gestate in, we’re going to have to make several types of gelatin, starting with clear.

Sprinkle 6 tablespoons of gelatin over the top of 1 cup cold water and allow to bloom for 15 minutes. While that’s blooming, combine 3 cups of water with 2 cups of sugar and 1 tablespoon of citric acid in a pot.

Over medium heat, melt the sugar and citric acid in the water.

It will start out cloudy, but as they combine, the liquid will turn clear. DO NOT LET IT BOIL.

Just when you start to see itty bitty bubbles forming on the bottom of the pot and the surface of the water starts to ‘shimmer,’ turn off the heat and remove the pot.

Immediately add in your bloomed gelatin and stir to fully combine.

As you stir, the gelatin will foam up and melt. Keep stirring until all your gelatin is fully dissolved. Add ½ of your bottle of pineapple oil.

Put the pot off to the side and allow to cool to room temperature. As it cools, the foam will disappear.

If after it’s cooled you still have a bit of foam left over, gently skim it off and discard it.

Step 6: Pregnant Pause

Prep your preggers mold by giving it a light spray of cooking spray, again going over it with a food safe paintbrush or wadded up paper towel to ensure that all the nooks and crannies are coated and that any excess is wiped up.

Carefully pour in your clear gelatin, trying not to splash or create bubbles. If you do have any bubbles, either skim them off or pop them with a toothpick.

To make the ‘pouch’ where our chestburster is going to go, gently place a bowl just slightly smaller than the size of the belly into the gelatin. It should float but displace just enough gelatin to make a dip.

Put your mold into the fridge and allow it to firm up for 2 hours. When your mold is set, it’s time to remove the bowl and do a bit of cosmetic surgery.

To remove the bowl, fill it with hot water and gently rotate it. The warmth will seep through the sides of the bowl and loosen the gelatin just enough that you should be able to pull it out. Do this quickly as leaving the hot water filled bowl in your gelatin too long will result in a huge runny mess.

Do this part VERY carefully and try to avoid pulling the belly section gelatin away from the edges of the mold. You want to keep the seal that’s been created by the gelatin against the mold material in order to prevent the next layer from seeping in and obscuring your chestburster.

Step 7: Sending Jr. to Her New Home

You should still have a bit of clear gelatin left over in your pot and odds are the higher ratio of gelatin to water we’ve used for this recipe has probably caused it to thickened up while sitting around even at room temperature. Go ahead and remelt it over very low heat. You want the temperature very low…just warm enough to melt the gelatin but not too hot. Too hot and the gelatin will start to turn cloudy.

Once it’s melted, allow it to cool completely to room temperature again.

Spoon about ¼ of a cup of your melted room temperature gelatin into the belly pouch of your preggers mold and pop it into the fridge for about 5 minutes or until it’s thickened a bit but not set.

Carefully place your favorite chestburster into the thickened gelatin, face down.

Curl the tail around in a spiral. If you find the tail doesn’t want to sit quite right, use a toothpick to hold it in place. Return the whole thing to the fridge for 30 minutes to firm up.

Step 8: All Cuddled In

While it’s firming up, make another batch of clear gelatin the same way you made the first batch and allow to cool.

When the second batch of gelatin is cool and the gelatin holding your chestburster is firmed up, gently pour in enough of the clear gelatin to completely cover your chestburster, but not up to the top of the mold.

You want to leave at least ½ an inch between the top of your clear gelatin and the top of the mold. ¾ of an inch is about perfect.

Allow the whole thing to solidify (it’ll take about an hour).

While it’s doing that, let’s make some more gelatin! YES, EVEN MORE!

Step 9: More Gelatin!

Because we’ll be coloring this batch, you don’t need to worry about babying it as much as we did the clear.

Go ahead and bloom the rest of your gelatin and mix it with your remaining water and citric acid.

Repeat all the rest of the steps for the previous gelatin recipes, but this time, we’ll be adding in the 1/4 cup sweetened condensed milk instead of the pineapple flavoring. This will make the gelatin white.

If you want to skip the condensed milk and make a dairy free version, this white from Wilton’s works well.

Step 10: Backing Up Your Pregnant Mold

Hopefully by now your preggers gelatin has set.

Pull your solidified preggers mold out of the fridge and grab a knife. Time for a little cosmetic surgery! Odds are when you filled your mold, it not only filled up the belly part, but a bit of overfill has probably gotten into the boob cups and probably the legs as well.

Use a sharp knife to carefully cut those away, leaving just your chestburster and the belly section. Again, be careful not to break the seal between the clear gelatin and the mold.

Because we’re all about recycling here, we’re going to add the pieces of clear gelatin you removed from the chestburster cast to your white gelatin mixture and heat it all up to melt the clear and combine it with the white.

If you find this makes the white less ‘white’ and more translucent, add a bit more condensed milk or white food coloring.

If you’ve purchased the same preggers mold I did, it will hold approximately 10 cups of gelatin.

After filling up the belly area you should have about 5 cups of gelatin left.

Divide your white gelatin into two separate containers, with one at 2 cups and one at just under 3 cups.

In the 3-cup container of white gelatin, add a few drops of red food coloring, brown food coloring and a drop or two of yellow to create a fleshy color. Do this one drop at a time, mixing as you go. This will allow you more control over the final color.

Once you have an appropriately fleshy tone and it’s cooled to room temperature, pour it over your entire mold, covering your chestburster and the back of the mold and filling it all the way to the top. Don’t worry about bubbles or anything on the surface of the gelatin as this will be the back and we’ll never see it.

Pop it in the fridge and let it firm up.

Step 11: In the Army Now

Because I'm recreating Ripley for this project, I wanted to stay as true as possible to the scene in Aliens 3 which meant making sure she was wearing the right clothing. In the film you can see her wearing a pair of Army green shorts and a matching tank top.

Combine any remaining gelatin you have left into one container (yes, even the flesh toned stuff) and add in a few drops of green and a few drops of red to get a nice ugly olive color.

Take a metal baking sheet with a raised edge and give it a good spray of food spray and give it a light wipe with a paper towel or food safe paint brush.

Pour your green gelatin into the baking sheet approximately ¼ of an inch thick and let it set up in the fridge.

Now let’s de-mold Ripley and get her dressed!

Step 12: Isn't Motherhood a Beautiful Thing?

To demold your fully set Ripley, gently tug the edges of your gelatin away from the edges of the mold using the flat part of your hand. Don’t pull too hard, you’re just breaking the seal between the gelatin and the mold.

Invert the mold over a serving platter or tray. The weight of the gelatin should pull the whole thing out easily (and trust me when I say this thing is heavy…we’re looking at about 8 lbs of gelatin here, so it should all just slide out on its own!)

Step back for a minute and admire your awesome monstrosity! Motherhood is such a beautiful thing…

Remember how I told you earlier to be careful when doing anything with the clear gelatin because you didn’t want to break the seal between the gelatin and the mold? Apparently I did break it just a bit along the top of the belly. You can see where a bit of the pink flesh gelatin got in between the clear and the mold. Luckily it wasn’t too bad and will be covered by Ripley’s shirt.

At this point you might notice that your mold (if you’ve used the same one I did) has very frilly scalloping running across the front of the boob cups. We need to get rid of those.

The easiest way to do this is to heat up the back of a spoon with either hot water or with a hair dryer and then gently run it over the gelatin. That will melt the gelatin and you can smooth it down.

Step 13: Let's Get Dressed

To make Ripley’s pants, cut a square of your green gelatin sheet about two inches wider than your gelatin mold and carefully drape it over the lower half of her belly, leaving the area where the gelatin is clear free so you can see the chestburster.

Use a sharp knife to trim off the excess around the hips and between the legs leaving about 1/4 inch all around. Tuck this additional 1/4″ of green gelatin under Ripley’s body.

To make the waistband of her pants, just cut a strip of green gelatin about ½ inch wide and drape it over the edge of the green gelatin pants top. If it doesn’t want to stay in place you can stick it down by lightly heating up the back of your spoon again and running it along the edge of the pant top to quickly melt a thin layer of gelatin.

Set your strip down on this and the temperature difference will solidify the liquid layer, gluing them together. If you find you have any tears or ripples, you can repair them by melting a bit of gelatin and dripping it over the areas you want to fix and allowing them to cool.

Once they’re cool, smooth them out using the back of your heated spoon again.

To make her tank top, repeat the same steps you did for her pants, draping a large section of gelatin over the belly.

Using a piece that is longer than what you actually need gives you a nicely wrinkled look like real fabric.

Of course, if you want a tighter tank top, simply use less green and make it hug her body more. This is where artistic license comes into play!

Gently cut away the scoop for the neck. Trim off the excess and tuck it under her body.

To hide the seams at the top and bottom of her tank top, again cut strips of green gelatin and glue them down. If you find while you’re doing this that you are running out of green gelatin, you can melt any scraps you have down and reform them in your flat pan. Just make sure to remember to grease it before you pour your gelatin or it might stick!

By now you should have Ripley fully dressed!

Step 14: Game Over, Man! Game Over!

To really make her stomach clear and make it possible to see your chestburster, gently hit it with your heat gun or a hair dryer.

Don’t use your spoon on this section as it doesn’t cover a large enough area at a time and may result in marking up the gelatin or tearing it. Just hold your heat gun/hair dryer over the very center of her belly for a few seconds until a thin layer of clear melts.

And that’s it! You’ve now got a fairly accurate recreation of poor Ripley in those moments after she discovered she was carrying the chestburster.

Store your monstrosity in the fridge loosely covered with plastic wrap until you’re ready to serve it.

While this is a gelatin product, because we used extra gelatin, making the consistency a bit thicker than regular gelatin, it should do much better out at room temperature than regular gelatin.

To really highlight the oddly beautiful nature of this disgustingly delicious project, try displaying it with a bit of light off to the side. It'll really show the 3-D effect of your chestburster.

Not only is this project perfect for Halloween, but if you think for one moment I'm not going to fully support someone making this for their own baby shower, or better yet, Mother's Day...well then you don't know me very well.

For even more disturbingly disgusting (yet decidedly delicious) recipes and ideas, you can see the rest of my Instructables here or go to my full blog at

Bone appetite!

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