Honestly, I’m not sure that this is the absolute best way to make these costumes. I struggled a bit with the exact mouth size and shape. Because I used only materials that I found thrift / cheap, there were some work-arounds that I needed to do. But they worked out fairly well. At the very least, perhaps I will have ironed out a few details that could be helpful for you.
First, I laid out one of my blankets and folded it into quarters so that I could find the exact center of the blanket. I put a safety pin in the very middle, so that I had a reference point. Then I draped it over my head to see what the best orientation of the blanket might be. Do I want the corners or the edges on the front, back and sides? If the blanket isn’t quite square, I need to decide which way it hangs best.
Remember that when you close the mouth, you’ll be lifting up the front of the costume. So make sure that you have enough fabric hanging in the front so that you’re still covered up when you close the mouth. Since you haven’t cut the mouth yet, you won’t be able to see what it looks like. It’s helpful to have as assistant to “wear” the blanket while you figure out how it hangs down. Mark key placed like where you want the crown of your head to be, and where the top of your upper lip will be. Remember that you’ll need to see out through the mouth, so the mouth hole should start at about your eye brows.
I struggled with the size and shape of the mouth. I ended up with one mouth being too big, and had to partially sew it closed, so better to go smaller rather than larger. I’d suggest a hole about 15” x 15”. Mark where you plan on putting the hole, then try the blanket on again and see what happens when you “close the mouth” to make sure you have enough fabric in the front that your waist doesn’t show when you lift up the fabric to shut the mouth.
Cut out the hole, and then cut a piece of your black fabric that is larger than the hole by at least a couple of inches on all sides. No need to be super tidy or exact – just lay the fabric down, cover the hole with your black fabric, and cut it to be bigger. I made the mouth hole oval – or in one case a slit – instead of round to accommodate the shape of the blanket. I’m not 100% sure that was the right move, but I’m also not sure it was a mistake. Like I said, I struggled a bit with the mouth shape.
Next, we’re pinning the fabric together to prepare for sewing. Check which side of each fabric is the “top” and which is the underside. Remember that you’ll want the right sides of the fabric to face each other. Pin the black fabric to the hole at four corners – at 3, 6, 9 and 12 o’clock, basically. This makes sure that the fabric is evenly distributed around the mouth. Then, find the point half-way between the pins for the blanket and the black fabric and pin it there. Then again half way between each of those pins. Again, the idea is to make sure that the black fabric is fairly evenly distributed around the mouth. It may gather up a bit – but that’s okay. You can see in the picture how I’ve pinned it at the four corners, and then halfway between two pins, and so on. Just keep pinning and measuring until you have the whole perimeter well pinned and the fabric fairly evenly distributed around the hole.

Then sew all around the mouth. If possible, use big stitches so that you can rip it out if you’re not happy with it. Because you’ll want to try to the costume on and make sure that you can see out of it, and that no one can see in. Try this in bright light, in regular light, etc. Take a flash photo with your phone and see if the face shows through. Now is your chance to change or add to the mouth fabric, if necessary.
At this point, it became clear that my black fabric sort of bulged out of the mouth a bit. So I put in another seam on the inside of the mouth so that I wouldn’t end up with black edges on the mouth. This worked well for two of the three costumes. On the third, it gave the costume “lips” so I ripped it out. You’ll need to experiment a bit, depending on how your fabric hangs.

Once I got the mouth sewn, I put on the baseball cap. I had already removed the bill, so it was a beanie, really. Then I draped the blanket over it and shifted everything around until I got the mouth in the right position. I pinned the hat into place, and then just tacked the blanket to the hat in three or four places by hand. (If I had it to do again, I’d put the cap on backwards to start, or buy caps without logos. When I went to stitch on the antennas, I had to stitch through the thick logo and it was a pain.) Again, it helps to have a person model the costume so you can get everything positioned correctly.
Now, the only things left are the eyes, the antenna, and fixing up the sides somehow.
I just used a hot glue gun to secure the eyes, and cut pupils out of black electrical tape (so that I could change their size or position if necessary.) For the antenna, I twisted three or four pipe cleaners together, leaving one end a bit splayed – like a chicken-foot – so that I could easily anchor each chicken toe onto the costume. This helped the antenna stand up. I stitched through the blanket and sewed the pipe cleaner to the hat underneath so it was secure and would stand up.
The next step was having someone try the costumes on and adjusting the sides / length. For two of the costumes, I cut the corners off the blankets so that I wouldn’t trip over them. For the third, I used safety pins to tack the blanket edges together at the side of the costume so they wouldn’t gap. I used safety pins because I was fearful that I would mis-sew the sides and the fabric would hang strangely. Using pins let me adjust it later, as needed, and let the fabric hang better.
Finally, I concocted a way to hold the lower lip in position using something other than my fist. There are many different ways to do this. One yip-yip costume tutorial suggested holding a rounded sponge inside the costume to make the lower lip. I rolled an old cloth placemat into a U shape and glued it to a paint stick.

I draped the lower lip over it, and held the stick in my hand. Worked great. The first and last pictures below show me just using my hand to hold the lip. In the green costume, I was holding up the brim of a baseball hat – you can see how the jaw is smoother. The jaw support thingie really smoothed out the look, and made the jaw easier to hold.
Overall, I’m very happy with them. They were inexpensive and fairly easy to make. And I got delighted response from people that I was looking for.


