I think what you're dealing with are Pear Slugs, which may or may not be what Beeman mentioned above. I used to see them on my pear trees and would just squish 'em when I found them. I don't see them anymore. In small numbers they didn't seem to do much damage, just mining the leaf surfaces here and there. They are a serious pear pest though in other parts of the country. Here is a link that might be useful: Pear Slugs

thank you

I am wondering if I should still cut them at the base and cover them up like I did last year? The are pretty big and thick at the base. They are even bigger now than they were in those pictures that I posted.

oh yes, cotinus! Thank you, Esh. I have been thinking about that shrub for days now as the leaf shape was so familiar but I just couldn't place it. I have a Cotinus "Grace" in my garden. Unfortunately mine is nowhere near this spectacular - the leaves have turned from blue/greenish to purple/plum, but have none of these wonderful reds and oranges. Maybe Grace needs a companion!