Monster mouths are one of my favorite parts of making monsters. So many choices. The simplest I've made was to cut pointy teeth out of felt and sew them in to the face. There are two ways to do this. One is by pinching the body fabric where you want the mouth to go, then sewing the pinched part with the teeth sticking out. The other is to sew 2 separate pieces of fabric together and making the seam the mouth. Again with the teeth sandwiched in between like the little yellow monster below.
The larger monster is my zipper pocket mouthed monster. Make a pocket out of scrap fabric and sew the opening of the pocket and the mouth opening together with the zipper sandwich in between. I had hoped to make my own monster version of a zipper pocket tutorial, but since I haven't yet you will have to find one of the many tutorials online for how to sew this kind of pocket into a bag. I used the same method here.
You can also embroider a mouth. I would recommend embroidering once you have the monster somewhat put together, but before stuffing. If you have at least the front and back of the head sewn together you will have a better idea of where the mouth should be and how it's all going to come together.
This time I went for a wire edged mouth. I haven't done this before but when I started playing with my piece of triangle shaped fabric I knew it needed to have a posable mouth.
First I cut a square of fabric for the inside of the mouth and sewed 2 corners to the two corners of my triangle pieces and then together where they met at the corners of the mouth. I used 5/8" seam allowance so that I'd have room to attach the wire to the allowance
I measured and cut a piece of wire equal to the perimeter of the green square pieced I had cut for inside the mouth. Then, using the longest and widest zig zag setting on my machine, I basted the wire to the seam allowance.
It was a little funky turning everything right side out. The wire at the point of the "beak" needed to be bent the opposite way it had been. I made sure that the corner where my wire was twisted together ended up at a corner of the mouth, not one of the beaks, so those corners were easy to reshape. Once turned I pinned all around the outside wiggling the wire as close to the seam as possible and used a zipper foot to top stitch around the whole mouth, securing the wire in place.
In order to keep the inside of the mouth from popping out when the head was stuffed I decided to learn a new skill and used my blind hem foot for the first time ever. I did not get a truly blind hem, but I did get the inside of the mouth securely sewn to outside and I'm happy with how it looks.
Now I need to figure out where to go from here. This turned out a little different than I imagined so my monster is going to be a little more involved than I originally planned, but I really love it so far.