The Joker in the Dark Knight, the Engineers, eggs and scary, bitey aliens from Prometheus and Alien:Covenant, the White Walkers from Game of Thrones, Conor O'Sullivan has been responsible for many amazing creatures and make-up effects over the past two decades. He talks to me about these and more, including working with Spielberg on the 'Jesus' moment, killing Brad Pitt and the new Joe Cornish film, Kid Who Would Be King.