Here's another photo, probably of the same thing but drier.

Here's my guess:

Bramble gall wasp

Diastrophus rubi

Now, I'm wondering if the two photos I posted, while located close together, might be different. The second one certainly seems like a wasp gall but the first might be a moth pupa?

Oh my gosh, Fori! I think you're right! Thank you :-)

You might get some clues about the gall (or whatever) by cutting it open. It looks like whomever was there left already...I'm just gonna go stand over there when you do it :)

If it's a blackberry or similar the correct plant forum here might know what it is.