When the question/response is "what" but not just "what", implying that
the speaker is responding in an
irritated or
frustrated or confused way, and that an additional "...is the problem" or "...is your issue" or "...the hell is going on" comes right after but is unsaid.
If the person wants, they can say the unsaid, for emphasis.
Examples:
Girl: (for the 10th time) "Um can you seriously come over here and
look at this?"
FriendofGirl: (busy doing
something else) "Whaz?!?!! What IS it? What is the deal with you, biznitch?!!"
or
NewsReporter: "...coming down the I-95 at 87 miles an hour, then flipping over and bursting into flame near the exit to Main street!"
Person
watching TV: (disbelief) "Whaaz...? I was just over there 5 minutes ago!!"
or
Mother: "Joey, will you GET over here right now?"
Joey: (playing down the street) "Maaaa, whaaaaazzz???"
or
Dude #1: (large black thing flying by at high speed) Dude, wtf?? Wtf was that?!?!
Dude #2: (looking confused/stoned/out of it) Huh, wha? Whaz goin on??