The director who shook up Disney and Hollywood animation with a mermaid, a genie from a lamp and a Polynesian princess

John Musker, who headed up ‘The Little Mermaid’, ‘Aladdin’ and ‘Moana’, is debuting a short film after announcing his retirement from a 40-year career. ‘At Disney in the 1990s, there was an emperor, but there weren’t 10 emperors’