Who is Duck?
After their first performance on the show, Rita Ora jokingly guessed they could be Ray Winstone.
Other guesses in the first week were All Saints star Melanie Blatt, Paula Radcliffe and Dame Kelly Holmes.
Another name added to the theories after their second performance was Mel C from the Spice Girls, while the others hazarded a guess at Mel C, Emma Bunton and Victoria Beckham.
Rita also told the audiences how it could be Heidi Klum while Jonathan Ross thought Chrissy Teigen.
Who is Daisy?
After their first performance on the show, the judges guessed Beverley Knight, Meghan Markle, Lindsay Lohan and Lulu.
Their second song on the show made the judges guess US singer Kelis, Mary J Blige, Macy Gray, Fleur East and Kate Hudson.