I found a great recipe on YouTube for making slime or Flubber and these guys not only helped in the process, they also played for hours and hours creating creepy, slimy things.
Fun, fun, fun times. Recipe below:
Mix 1 teaspoon borax in 1 cup of water. Stir until the borax is dissolved.
In a separate container, mix 1/2 cup (4 oz) white glue with 1/2 cup water. Add food coloring, if desired.
While stirring, pour the borax solution into the glue solution.
The slime will become hard to stir after you mix the borax and glue solutions. Try to mix it up as much as you can, then remove it from the bowl and finish mixing it by hand. It's okay if there is some colored water remaining in the bowl.
The slime will start out as a highly flexible polymer. You can stretch it and watch it flow. As you work it more, the slime will become stiffer and more like putty. Then you can shape it and mold it, though it will lose its shape over time.
Don't eat your slime and don't leave it on surfaces that could be stained by the food coloring.
Store it in a plastic bag or covered container in the refrigerator.