Because Bert is fat and stupid and doesn't have any friends... hahah
The sizing is spot on standard sizing (same as our classic tees)
The "Fatagonia" T-shirt is 3.6 oz. Ultra Jersey (not Ultra New Jersey) 65% polyester/ 35% cotton blend, side-seamed, taped neck and shoulders with double-needle sleeve and bottom hem. Super duper soft comfortable and form fitting (but not Under Armour type fitting).