Katie

“You are here to learn the subtle science and exact art of potion-making. As there is little foolish wand-waving here, many of you will hardly believe this is magic. I don't expect you will really understand the beauty of the softly simmering cauldron with its shimmering fumes, the delicate power of liquids that creep through human veins, bewitching the mind, ensnaring the senses. . . I can teach you how to bottle fame, brew glory, even stopper death — if you aren't as big a bunch of dunderheads as I usually have to teach.”
― J.K. Rowling, Harry Potter and the Sorcerer's Stone

“We won't be seeing you,' Fred told Professor Umbridge, swinging his leg over his broomstick.

'Yeah, don't bother to keep in touch,' said George, mounting his own.

Fred looked around at the assembled students, and at the silent, watchful crowd. 'If anyone fancies buying a Portable Swamp, as demonstrated upstairs, come to number ninety-three, Diagon Alley — Weasleys' Wizard Wheezes,' he said in a loud voice, 'Our new premises!'

'Special discounts to Hogwarts students who swear they're going to use our products to get rid of this old bat,' added George, pointing at Professor Umbridge.

'STOP THEM!' shrieked Umbridge, but it was too late. As the Inquisitorial Squad closed in, Fred and George kicked off from the floor, shooting fifteen feet into the air, the iron peg swinging dangerously below. Fred looked across the hall at the poltergeist bobbing on his level above the crowd.

'Give her hell from us, Peeves.'

And Peeves, who Harry had never seen take an order from a student before, swept his belled hat from his head and sprang to a salute as Fred and George wheeled about to tumultuous applause from the students below and sped out of the open front doors into the glorious sunset.”
― J.K. Rowling, Harry Potter and the Order of the Phoenix

“Fred and George turned to each other and said together, 'Wow, we're identical!'

'I dunno though, I think I'm still better looking,' said Fred, examining his reflection in the kettle.”
― J.K. Rowling, Harry Potter and the Deathly Hallows

“How do you feel, Georgie?" whispered Mrs. Weasley.
George's fingers groped for the side of his head.
"Saintlike," he murmured.
"What's wrong with him?" croaked Fred, looking terrified. "Is his mind affected?"
"Saintlike," repeated George, opening his eyes and looking up at his brother. "You see...I'm HOLEY, Fred, geddit?”
― J.K. Rowling, Harry Potter and the Deathly Hallows