I swear I’ve never seen a caterpillar move as fast as this one—I had a hard time keeping up with it. Every time I’d got the camera organized it’d have shot past the lens at doublespeed. I finally started setting up ahead of it and got this shot as it whizzed by. I was motivated to keep trying—it’s such a pretty little thing.
It’s Lophocampa maculata, a spotted tussock moth caterpillar. I found quite a bit of information about this little guy and his cousins here.