This fella, apparently intent on eating the whole thing, is the larvae of erinnyis ello – the Ello Sphinx Moth.
Fully mature, he has a wing span of 2 15/16 to 3 5/16 inches. I've seen only one sphinx moth in this garden, years ago and at night. I'm really careful not to put caterpillar host plants in my garden - they're just too destructive. Nothing I have is a particular lure for this moth. However - this is Florida, he has lots to eat elsewhere in the neighborhood, and he found his way here. I inspected all my plants and found no siblings...and I'm thinking of pulling up my neighbor's poinsettia plants one dark night. This moth loves them.
The black spot on his back is a fake eye that he flashes to intimidate predators such as myself. With the eye and the markings on his head and back, he tries to look like a small cobra!
That's my hand behind him. Big big bug.
So, back in the safety of the house, I've been working on a new knitting project - I'm making socks! The caterpillar might not intimidate me, but double point knitting needles sure do. But so many people make such beautiful and funky socks. I need some.
A little research on Ravelry, and I found 'Marie's Basic Sock Pattern' - perfect for a beginner. And check it out! It's so easy to please me...I like this awful yarn :-)
I just don't think this caterpillar has redeeming qualities, but I admit I enjoyed reading about him.