For this project you will need scissors, thin cardboard, cloth, tape (any type will work), construction paper, a hot glue gun and safe water-based paints.
Step 1: Beginning Top Half
First, you're going to need to cut a piece of cardboard 1.5 feet long and 1 inch wide. Then, take the mask's frame and wrap in around your head, just above the ears, not too tight; cut off the excess until it sits pretty snug like a crown, and then tape it. You will need two 1.5 feet pieces of cardboard, 1 inch wide. Tape one side of one of the cardboard pieces inside the front of the "crown," then, take the end and put in inside the "crown". Cut off the excess, and tape it; making a mohawk and repeat this, left side to right side, make a cross. With two more, piece 1.5 feet long, but a half inch wide, and tape one end on the left side of the "crown," in between the last two pieces. Go over them to the other side, and make it snug. Cut off the excess again, then tape it down. Repeat this on the right side. After this, congratulations, you have made your head support.
Step 2: Building the Face
To begin the 2nd step, you will need to cut out 3 foot long pieces of cardboard, about a half an inch wide. Take one, and tape the tip to the front of the "crown", and bring the other side to your chin, cutting off the excess. Take the other one and tape the tip to the left side, about to your ear and bring the end down. Cut to about where your chin is and repeat with the last piece on the right side of the "crown". Now, cut out another 1 foot long piece of cardboard and 1/2 an inch wide. Put the mask on. This should be easy: leave a marker where your nose is (try tape or just your finger). Take the piece of cardboard to the center of the mark. It should go under the front piece where your nose was. Tape it there, then stretch it to the side pieces, making sure your head still fits. Cut off the excess and tape it down. You'll then take two 4 inch long pieces (the same width as last time) and tape the end to the point on the top crown, where your eye ends. Meet at the bottom, connecting to the last piece going across the nose and repeat. The side at this point should look like a weird football helmet, but you can clearly tell the front and the sides and where the eyes are going to be.
Step 3: Making the Face/painting
With what you've made, now you're going to cut pieces of construction paper, then taping them over the "football helmet." This construction paper should almost cover the "football helmet," except for the cardboard around the "eyes." For this next part, you should take some tape, and slowly put it around the eye, thus shaping the size of your eye. You should have a mask now, that doesn't have to look great. You're going to paint over this, with black water-based paint over the entire outside of the mask. When this dries, do the same thing with a dark green water-based paint. Take the cardboard and cut out thin 1 foot long pieces (make around 15). Cut it in half to make around 30 tentacles. Hot glue them onto the mask, putting the smaller ones at the top, and bigger ones on the bottom (cover the mask like a beard). Once the glue dries, mess around with them. Spread them out and make each piece a little different. You can cut some to make them shorter, or twist it, making it look more like a tentacle.Then take some cloth (that you can see through) cut its to the shape of the eyes and inside the mask tape it to make spooky white eyes. Now, cut out four 2 inch wide, 1 foot long pieces of cardboard. These will be the main tentacles. They should be big enough to cover the other tentacles. To glue them onto the mask, cut them in half and stop at the 3/4 mark. This should make them stay together, but still bendable, so you can bend them in any direction to make them look more like tentacles. You can cut the bottoms of any of them to make some shorter than other. Once that dries, all you have to do is paint it a greenish yellow. Make sure to get the bottoms of the tentacles. After that, you are done. Enjoy your Cthulhu!