1. (n) Internet forum thread that features disproportionately large amount of win. Usually originates at the expense of a forum member posting something amazingly stupid. Can also originate from an image that gets Photoshopped many times throughout the course of the thread in pursuit of hilarity.
Someone asked for a picture of an FJ Cruiser and a porta-potty on The Car Lounge Forums and the consequent hilarious replies eventually elevated the thread to epic thread status.