This morning I had a look around my yard after being away for the past week, and I met this fantastic creature on a leaf of one of our cultivated hazelnuts:
Its body was awkwardly contorted, and it took me a lot of tries to get a photo with all (or most) of it in focus.
When it started walking around, I was surprised to see that it was able to unfurl those tendril-like appendages (even harder to get in focus when it was in motion, but these photos will give you some idea).
This strange beast is a horned spanworm (Geometridae: Nematocampa resistaria), something I’ve encountered only a couple of times before, and this one was the largest and fanciest. Here’s a very young one I found on a black cherry leaf on 6/13/2013:
And one found on a woodland sunflower, 6/8/2019:
Although today’s larva was the first I’d seen in my yard, I spotted an adult of this species on the basement ceiling on 7/6/2014:
The caterpillar seems like something that belongs in the tropics, and sure enough, here’s a video showing a Nematocampa larva in action in a Peruvian rainforest: