- (colloquial, rhetorical question) Said to express surprise due to a perceived drastic change of behaviour of a person.
2000 May 15, “Letters to the editor”, Roanoke Times, Roanoke, Virginia:
- Who are you and what have you done with the "real" editors of The Roanoke Times?
2002 November, Tom Gliatto, “Local boy makes good”, People, volume 58, number 22, page 114:
- One thing she has noticed over the years, Dorothea says, is that "he's developed more of a sense of humor. Now, when he'll crack a joke, I'll say, Oh, my God, who are you and what have you done with my husband?"'
2009, Suzanne Brockmann, Into the Fire, page 49:
- "Who are you and what have you done with Izzy Zanella?" she finally said. / "Go on," he said. "Mock me. The one time I'm being serious and trying to do the right thing."