The Wiesn King features a flame-grilled beef patty, Bavarian-style cheese spread, onions, mustard, and pickles on a sesame seed bun. Besides the beef, it's all stuff you might eat with sausage at Oktoberfest or a biergarten.
While it's unclear what is in Burger King's version, obatza can be made differently from place to place, an example of ingredients for it includes Camembert, butter, horseradish, caraway seeds, paprika, and salt (sometimes there's also a little bit of beer in it).
Photo via Burger King Germany.