Gather your supplies. Unless it's close to Halloween, it's not so easy to find a skull in stores. A couple of good places to look are online and in pet stores (aquarium aisle).
Heat your water in the microwave for about 30 seconds. Mix the glue with the water. You can adjust the ingredient amounts depending on how much slime you need.
Add the desired amount of food coloring to your glue mix. Oozes come in a variety of colors, including green, red, orange, etc.
To make the Borax solution, you will need 1/4 teaspoon of Borax and 1/4 cup of water microwaved for 30 seconds. Stir until the Borax is dissolved.
This is probably the most important step in the process. Start stirring your glue mix rapidly. Very slowly add a few drops of the Borax mix while stirring. Stop adding when your slime is the desired consistency.
Your slime should look similar to this.
In order to get this look, I put my skull on top of a clear medicine measuring cup. I draped the slime in layers over the skull and cup and threw in a broken weapon and some coins. The slime eventually oozes off, but is reusable, so store it in a container and save it for later. Check out other fun projects at World of WarCrafts.