What the ....?

I first noticed this little sucker when I was moving a branch that had fallen, felt something squishy, and smelled something gross. I'm not going to lie -- it freaked me out. It looked like something from Alice in Wonderland. I figured it must be a caterpillar, but what was it doing out in fall? I had never seen anything like it. Despite the fact that H wanted to squish it, I moved it onto a tree. And then it did this:



Yikes! Turns out though, it's a Canadian Tiger Swallowtail (I think, according to Google images). And it does emit a foul odor when threatened. And has an "orange osmerterium" that looks like a forked snake tongue. Pretty gross. But pretty neat.