If you need a costume and a store-bought one just doesn't fit the bill, you can impress your friends with your resourcefulness and make your own round costume out of paper mache. Decorate you costume to make it into anything spherical -- you are limited only by your imagination.
Inflate a large balloon. Decide how big you want your round costume to be and get a balloon that size. You can get oversized balloons as large as 72 inches at a craft store or from an online balloon retailer.
Make your paper mache paste. A flour paste can be made by mixing 1/4 cup of sifted flour with 1 cup of cold water. Mix until you have eliminated all of the lumps, then add the mixture to five cups of boiling water. Stir for two or three minutes as the mixture thickens. A thicker paste can be made using the same method, but with 1 cup of flour and 3 cups of water.
Cut a newspaper into strips about two inches wide. You can use strips the length of the whole newspaper or cut them in half for smaller round costumes.
Coat your first strip in paper mache. Dip it in the flour paste, remove it and run it between two fingers to remove excess paste.
Apply the strip to your balloon. Use your fingers or a brush to press the strip flat to the surface of the balloon and remove any bubbles trapped underneath the strip.
Repeat steps 4 and 5 until you have covered your balloon with paper mache. You can apply up to three layers of paper mache at a time, but if you apply more than that it may take too long to dry.
Dry your paper mache balloon for at least 24 hours. You need your paper mache to be completely dry before you do anything else to it.
Cut holes in your paper mache globe for your arms, legs and head. (The balloon mould will release easily with popped.) Use scissors or a small handsaw to make the holes. Make sure you cut the hole for your legs large enough to get your whole body through.
Decorate your round costume. You can decorate your costume with just about anything. Punch holes in the costume to tie things to it, or paint it to resemble a familiar object.
Paper mache paste also can be made using wallpaper paste or glue. You can add paper mache features to your round shape by attaching pieces of cardboard with masking tape and covering with paper mache. Covering your dried paper mache with gesso will make it a little sturdier.