If the person wants, they can say the unsaid, for emphasis.
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?!!"
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!!"
Mother: "Joey, will you GET over here right now?"
Joey: (playing down the street) "Maaaa, whaaaaazzz???"
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??