Duke of York's theatre, LondonShapeshifting creatures take centre stage in Katy Rudd's production that terrifyingly evokes childhood nightmares and family trauma Neil Gaiman's short, lyrical 2013 novel inhabits a no man's land between childhood nightmares and the disappointments of adulthood which is so terrifyingly evoked in this National Theatre transfer that it reframes the idea of a good family show. We're all us…