Ron menciona isso durante o segundo livro. Fred (ou George, um dos gêmeos) transfigurou seu ursinho de pelúcia em uma aranha gigante, e o modo como movia suas pernas mentalmente o marcou para a vida toda.
"I just don't like the way they move ....
Hermione giggled.
"It's not funny," said Ron, fiercely. "If you must know, when I was three, Fred turned my - my teddy bear into a great big fiIthy spider because I broke his toy broomstick .... You wouldn't like them either if you'd been holding your bear and suddenly it had too many legs and. . . "
He broke off, shuddering. Hermione was obviously still trying not to laugh.