The Koch Snowflake is one of the earliest fractals described, long before the word 'fractal' was even coined. It's easy to describe - just start with an equilateral triangle, then take each side and add a triangle to the middle, one-third the size of the original, then repeat for each smaller edge, again and again, to infinity. It's a shape with a finite area, but and infinitely long boundary! So, be glad this is only an approximation to a few iterations, or else your printer would take literally forever.
This shape was one that I read about as a kid and thought was pretty awesome. I remember writing programs to plot it on screen - it only takes a few lines of code - but now I've made a really-real one! How cool is that? One day I might get less excited about how cool 3D printing is, but today is not that day.