EmmaStone Lake And Palmer
Star of Easy A, Zombieland and La La Land, who caused much confusion on Wittertainment when - as a slightly less well-known actress - she introduced the Oscar nominations alongside Seth Macfarlane in 2013. (Though not as much confusion as her name would cause at the 2017 Oscars...)
Simon introduced her as Emma Stone as he threw to the broadcast, but by the time he picked up again she had become Emily Stone (which happens to be Emma Stone's real name, but that is hardly the point). Mark then went one better and referred to her as Emma Watts, who is in fact a TV actress best known for playing a police officer on Coronation Street. Had the programme gone on much longer, Stone would have likely ended up first as Hermione Grainger and eventually Bess McNeil.
In the end, Simon plumped for the prog rock-referencing EmmaStone Lake And Palmer. We wrote on Witterpedia before the 2017 Oscars: "It will be seen - in the light of La La Land's likely Oscar success - if she is any more memorable this time around."
We now think she will be.