Look for a glowing red pentagram, located near one of the town's corners. It's positioned next to the electrical tower that you can see off to the far left, if you stand near the base of the water slides at the community pool. Once you place five human or goat bodies on the pentagram, you will become the Devil Goat. Note that if you're looking to expedite the process, you can become the Goat King and quickly summon goats to the desired spot. When you become the Devil Goat, it's possible to fly if you summon a Black Hole and enter Rag Doll mode.