Retna Ltd. 1 / 8

Music mogul Simon Cowell has shed his "Mr Nasty" image for good by stepping in to save a critically-ill child.

The "American Idol" judge, known for his caustic comments and scathing reviews of contestants, recently showed off his softer side by signing up to become patron of Children Hospices U.K, a charity which helps sick kids.

The star was moved by the plight of 19-month-old Sophie Atay, who has been diagnosed with a rare, aggressive cancer known as neuroblastoma.

RELATED: Become a fan of Wonderwall

The tot's parents have been trying to raise $800,000 to send Sophie to New York to receive specialist treatment, and when Cowell heard of the appeal, he stepped in with a pledge of money to make sure they hit their target.

RELATED: Follow Wonderwall on Twitter

Cowell's protegee, former The "X Factor" winner Alexandra Burke, broke the news to Sophie's mother Karine, telling her in a phone call, "I've spoken to Simon and he's going to put the rest of the money that you need towards it to give her the treatment. I really hope that she's OK and that she can go over there and fight it."