Fatty Box Share definition Flag one of those new boxes from Taco Hell, with like five tacos/burritoes in it! Only a true fatty could finish the whole damn thing! A: I dunno what to get B: Why don't you get a Fatty Box, fatty? A: Hmm good idea! Fatty Box by Blaise Thaine March 6, 2010 0 0 Get merch Get the Fatty Box mug. Buy Now — $32.95 See more merch