- "Monday. This reminded Harry of something. If it was Monday — and you could usually count on Dudley to know the days the week, because of television — then tomorrow, Tuesday, was Harry’s eleventh birthday. Of course, his birthdays were never exactly fun — last year, the Dursleys had given him a coat hanger and a pair of Uncle Vernon's old socks. Still, you weren't eleven every day."
On 1 September, 1993, while en route to Hogwarts Castle aboard the Hogwarts Express, Harry Potter's Sneakoscope started whistling, and Ronald Weasley stuffed it into one of this old socks to muffle the sound and Harry kept it there for over a year.
- Harry Potter and the Philosopher's Stone (First appearance)
- Harry Potter and the Prisoner of Azkaban
- Harry Potter and the Goblet of Fire