The what?! According to wikipedia, the interrobang is “a rarely used, nonstandard English-language punctuation mark intended to combine the functions of a question mark and an exclamation point.” Example:
You pierced your what?! = You pierced your what‽

Concocted by advertising mogul Martin Speckter in 1962 to pack a punch in ads, it never quite caught on. Some of the proposed names for the bright-eyed punctuation mark included exclarotive and exclamaquest, but interrobang won out. It’s definitely catchy, but it sounds a little like some type of horrendous act that the UN would include on its list of war crimes.

Find out more about the interrobang here on wikipedia.