A dusty, beat up plastic bowl filled with popped pimples and zits. Horse semen and leprechaun pubes is then added to all the particles in the bowl, and then it gets blended. When the blending is done, you have now created the mixture, SHAM™. It is then poured into a zip-lock bag that has holes punched in it. You place the SHAMBAG™ inside someone's pillowcase, so when they go to sleep, the SHAM slowly oozes out onto their face.
Hey, if you're going to prank Sam, just place a SHAMBAG™ under his pillow.