San Onofre Switcheroo

The act of leaving an unwiped, unflushed turd in the toilet of a public restroom. Typically, the initiator will take a dump in one stall and then switch to another stall to wipe and flush before leaving. The intent of a San Onofre Switcheroo is to confuse/disgust those who enter the stall next and make them believe that there is someone out there who didn't wipe before leaving.

Aaron: I'm bored, I think I'll leave a San Onofre Switcheroo in the restroom so it can surprise whoever uses the stall after me.
Zach: Dude, you're disgusting and childish.