As the father-of-three met the co-creators of the book at a Tusk Trust event, William said: 'I know who you are. It’s a big hit in our household, The Gruffalo.'
Donaldson and Scheffler decorated one of 21 model rhinos with characters from their book, The Ugly Five, as part of a project to raise awareness of the threat facing rhino populations at the hands of poachers.
The Gruffalo has also been adapted into a play which was been performed on London’s West End, as well as the Sydney Opera House, and also lends itself to a 2009 Oscar-nominated film of the same name and stars Robbie Coltrane, James Corden and Helena Bonham Carter.