David Walliams: I wanted to write a book about 'pure evil' Simon Cowell
Best-selling children's author David Walliams has revealed he once wanted to write a book with Simon Cowell as the leading villain.
The 44-year-old said he thought he would write a book "about a record executive who's on TV who doesn't have a heart, he has a mechanical heart".
He was responding to a question from a young boy in the audience at the Radio Times Festival, who asked if Walliams had ever considered writing about his and Cowell's "romance".
The author said: "I was a bit worried it would be the obvious choice. He would make a great villain because he is actually pure evil."
Walliams suggested the music mogul would probably want Brad Pitt to play him in any film adaptation, but joked that Dale Winton would be a more realistic choice.
He added that he felt some celebrities had given children's books a bad name: "We're not going to mention any names... cough... Katie Price," - a barbed reference to the glamour model's Perfect Ponies series.
Walliams also admitted being a lazy reader when he was younger. He said he "wasn't a big reader" and "preferred TV", before discovering Roald Dahl's Charlie And The Chocolate Factory, which sparked his love of reading.
He was speaking to crowds to promote his new book, Grandpa's Great Escape, about a confused grandfather in a nursing home who thinks he has been sent to a prisoner of war camp and plans a daring escape with his grandson Jack.
Walliams told the audience he was most proud of his latest book as it tackled a difficult topic and said the idea started after he saw "a very, very emotional film about a lady who had Alzheimer's".
"Children know how to play and sometimes when people are in a confused state when they are older, they're sort of playing too."
He said the book was not based on anyone from real life but he was "thinking of my own grandfathers - one of my grandpas was in the Home Guard and the other was in the RAF".
"It is a special bond between grandparents and children. They let you stay up a little bit late, give you food you shouldn't normally have, so you often really look forward to spending time with your grandparents."
He treated a rapt and giggling audience to numerous readings from his latest and previous books.
He said he had done a lot of research ahead of writing the book, because "children like to write you letters when you've made a mistake in the book - they love that more than anything".
He said he spent time at the Imperial War Museum and took a flight in a Spitfire in preparation for the book.