Roflwalrus
When someone makes such an epic fail, does something so amazingly stupid, or something that's along the lines of "rofl", "roflcopter", "roflstomp" etc., but the situation is so large that it demands for a gigantic mammal's name to be incorporated.
Friend: (reading a pick up line) "I just had to come talk with you. Sweetness is my weakness." Well, then you better stay away from the chocolate fountain, buddy.
You: ROFLWALRUS!
You: ROFLWALRUS!