Sometimes used synonomously with the verb form "to creeper", the act of commiting creeper style.
Bob: "I was up watching ALF reruns when she went to bed, but I creepered her before I fell asleep... so it's all good."
Tommy: "I hear yah, doggy style, creeper style... at least you have a chic."
friend: "What happened, Skipper?"
mechanic: "I totally boinked this girl creeperstyle while changing her oil!"