Quote from : Harry Potter and the Order of the Phoenix Book

And this is Nymphadora-" "Don't call me Nymphadora, Remus," said the young witch with a shudder. "It's Tonks." "-Nymphadora Tonks, who prefers to be known by her surname only," finished Lupin. "So would you if your fool of a mother had called you 'Nymphadora,' " muttered Tonks.