Really cool fractal patterns. Fractals are shapes that are infinitely self-similar at every scale of magnification. So as you zoom in on each little squiggly arm, you realize that it also possesses its own squiggly arms that are the same shape as itself, and you can zoom inwards into infinity finding the same patterns forever.
Crystallizing water forms repeating patterns in snowflakes and on frosty surfaces. The patterns have inspired claims about the power of consciousness to affect matter, as well as one of the first described fractal curves, the Koch snowflake.