Gak Recipe
You will need:
3.5 oz of Elmer's Glue-All
Liquid Starch
Red, yellow and green food coloring
Pour Glue-All into mixing container. Begin adding liquid starch slowly, working it into the glue until the mixture no longer sticks to your hands. Ultimately, you should be able to pull and twist it and mold it like Ghostbusters Slime (do you get the visual?). Remember to add the starch slowly. It is easier to add more starch if you need to than to add more glue. In fact, if you find need to add more glue (the mixture won't hold together), you'll probably need to scrap the recipe and start over.
Once you get the Gak compound to the consistency you need, add 5 or 6 large drops of yellow food coloring. Mix in. Then add 2 or 3 drops of green food coloring and enough red to make the substance a sickly brown-yellow color. Don't worry if the color ends up slightly psychedelic—you can use that as a joke later ("Have you ever seen neon yellow pus? Me neither and I wouldn't want it inside me!"—the groans and whines are well worth it). This recipe will last you a couple of days if you store it in the refrigerator. Eventually, it starts to break down and get syrupy. The best mixture I ever made lasted 3 weeks. Think positively.