Favorite silly HP fun fact?

I’d like to hear some of your tidbits you might’ve picked up through the years. One of my go-to’s is how Tom Marvollo Riddle is an anagram for “I am Lord Voldemort” but because it’s a plot-relevant “Easter egg” it has to apply to all the various translations of the books. Thus, in the French publications, Voldemort’s middle name is Elvis