Find Woody the ghoul for Percy. Try the Den

You receive this quest in Gecko, at the Survival/Gear shop at the Gecko Junkyard. Talk to Percy, and he'll tell you how he's worried about his friend Woody, who's disappeared someplace. As the game recommends, go to the Den.

At the Den East Side, go to the guy that supposedly has an ancient Egyptian mummy, which is south, in the haunted house. Talk to him and pay him $25 to have him show you the "mummy". You will recognize that the mummy is, in fact, a ghoul wrapped in toilet paper. Wake Woody up and tell him to run.

You'll receive some XP and Percy will give you several Rad-X and Rad Away's.