Nonchalantly stated in the movie "I hope they serve beer in hell", Snatch Napkin is a derogatory term used as an aid in the vocabularies of hometown comedians in making fun of braindead sluts. It can almost literally be translated to: whore, slut, or any of the other fine words used to describe the combination of beauty and stupidity.
guy: "you're such a snatch napkin hahaha"
girl: "oh my godddddd whats thattttt?"
guy: "oh it just means your really pushy, you know, like you like to snatch things away from people and shit. don't worry about it baby."
girl: "ohhhh, well im a total snatch napkin then!"
Ok, everyone has that kid at their highschool that is just ridiculously big and swoll for no reason. You know, anybody who doesn't have shit for brains but can bench press 3 times stephen hawkings I.Q. level? There can only be one explanation for this phenomenon: Monster Tard Powers
person one: "hey bill, you know that muscle queen in our math class that thought that pi was literally pie?"
person two:"Yeah i remember that broham"
person one: "I saw him at the gym the other day benching 415"
person two: "dude he must have used his monster tard powers."