Rita Skeeter. She wasn’t fully explained as such, but it’s generally assumed. The first description of her was:
‘Her hair was set in elaborate and curiously rigid curls that contrasted oddly with her heavy-jawed face. She wore jeweled spectacles. The thick fingers clutching her crocodile-skin handbag ended in two-inch nails, painted crimson.’
Harry Potter and the Goblet of Fire, Chapter 8, The Weighing of the Wanda