Lol...
Melanie, you wrote:
Here's a pic of a Fir Tussock Moth (which actually eats oaks and cypress).
I thought I was supposed to be looking at a moth rather than a caterpillar. [It would be a
caterpillar, of course, that would be eating the oak or cypress, not a
moth, but I missed that technicality
]
Looking at the photo inline, I thought you must have accidentally posted the wrong photo. I actually thought it WAS a slug until I enlarged it. This was one really convincing mimic!