These butterflies (Papilio tempestae) have wings of an undistinguished yellow with black mandelbrot patterns, and fractal edges of infinite length. A quantum weather butterfly can "create weather" merely by flapping its wings. It is possible that this is a sexual characteristic, that a male quantum weather butterfly will flap its wings and create, perhaps, a freak gale a few miles off, to show off its powers so to court a female quantum weather butterfly. Also, a quantum weather butterfly can make a small thunderstorm over, for example, the head of a bird that is trying to eat this butterfly, so the butterfly can flee the place and the bird might remember not to pursue such butterflies another time.

The major appearance of the quantum weather butterflies is in Interesting Times, when the Lady uses a seemingly endless flock of them to create a storm over Hunghung and the plains around it, on the Counterweight continent.

According to Vetinari in Feet of Clay, "the bodily fluids of the caterpillar of the Quantum Weather Butterfly will render a man quite, quite helpless."

Used to have a book on tape of interesting times...

...takes me back...

Why?

Is this Terry Pratchet or something else?

Did i mention why?

I'm a mite bewildered as well, but hey: roll with it...

Drunken spamming? Never thought it would come from Xedi.

Are quantum butterflies biological creatures? Or a phenomenon of nature? If all quantum butterflies are wiped out will weather cease? Are they an endangered species because the lack of natural disasters recently might imply a decrease in mating for these creatures.

they are wonderfully fractal and chaotic creatures, from what you have described, but how are they quantum? Can they go through two windows at once?