Nasty asstoilet paper, mainly at work, that has finger prints of the asshole before you that got their finger dirty while wiping and left their mark behind for you to discover.
Variation of the word "puppy". "Puppy" becomes "poopy", and therefore "poopy" becomes "poopster" by the nature of human beings to add a -ster at the end of everything.
Invented in the year 10,567 BC by a scribe named Rich Siegel, this form of self-amusement has a long storied yet secret history. Sort of like the Masons and their lore, but people don't talk about it as much. From ancient times, people have been sexually aroused by their own poop and pleasured themselves in various ways while pooping, to further enhance the experience.