What's that?" he snarled, staring at the envelope Harry....

“ What's that?" he snarled, staring at the envelope Harry was still clutching in his hand. "If it's another form for me to sign, you've got another -""It's not," said Harry cheerfully. "It's a letter from my godfather.""Godfather?" sputtered Uncle Vernon. "You haven't got a godfather!""Yes, I have," said Harry brightly. "He was my mum and dad's best friend. He's a convicted murderer, but he's broken out of wizard prison and he's on the run. He likes to keep in touch with me, though...keep up with my news...check if I'm happy.... ”

J.K. Rowling

From : Harry Potter and the Prisoner of Azkaban