Serendipity 3 is not longer the “top dog.” Previously, they created the most expensive hot dog at $69 — but there’s a new $80 dog in town. In Boston, the McMullen Dog was created by Troy Goodwin and Brockton Rox executive Chef Ben Glanz; The half-pound, all beef foot-long is rolled in truffle oil, deep fried, coated in porcini mushroom dust, sprinkled in white truffle shavings, and topped with creme fraiche and caviar.