What real historical facts sound like J. K. Rowling added them after writing history?

The story of the Emu War in Australia always hits me as something straight out of a fantasy novel. Imagine the military actually losing a tactical operation against a bunch of giant flightless birds. It sounds exactly like some chaotic, magical mishap you'd read in a wizarding book, but it actually went down in the 1930s. Men with machine guns struggling to hit fast-moving emus is just too ridiculous to be real life, yet here we are.

Then there's the dancing plague of 1518. People just started dancing uncontrollably for days on end in the middle of the street until they literally dropped from exhaustion or died. If you put that in a book, people would call the author lazy for coming up with such a weird plot device, but it’s a documented historical event. It feels like someone just wanted to add a bit of dark, unexplained humor to the timeline of humanity.