Very, very hungry caterpillar! The fennel in my garden is pretty much all gone. I buy this little one a little fennel bulb (organic) with leaves still attached every 2-3 days, and he pretty much strips the whole thing each time.
He was about half an inch long, and about a 1/8 of an inch wide, when I picked him off the fennel outside, he was a tiny little thing. He looked like this:
(This photo is not mine, it is from this website, this is one of the websites I used to identify the caterpillars in my garden.)
Now, only 2 1/2 weeks later, he looks like this:
Comparatively, he looks like a monster! And a totally different species. But he's not, these caterpillars just change a lot during their lifecycle.
He is about 2 1/2 inches long now, and about half an inch thick at the head. Crazy how fast they grow!
He is called a yellow swallowtail butterfly, also known as anise swallowtail, for the fennel they prefer to grow on. They are beautiful butterflies!
I usually prefer to let them grow naturally, but all the others (almost 20 caterpillars that I counted) all got eaten by predatory wasps or birds. This was the last one! I really wanted to give this one a chance at least to make it to a butterfly.