We’ve a nocturnal visitor. He/she/it leaves deposits behind:

Here’s another take:

We’ve seen opossums before in our back yard. Our neighbor across the street reports an abundance of raccoons in the vicinity. We smell skunk regularly.

I tend to think it’s a striped skunk (Mephitis mephitis).

But I really don’t know so I’m throwing it out there! What’s crapping in my yard?