"Thank you, sir. I'm not from this side of town, but you guys give really weird welcome gifts."

Throw it back at him as a return gift with a thank you note

No, they should put their own dog's feces in a brown bag, put it on his porch, set it on fire, knock on his door/ring the bell, and then run, baby, run.

you know, like in Billy Madison.

For some reason, when I read this FML, this song popped in my head to a tune from Beauty and the Beast about her little town:
I walked my dog like I do e-ve-ry-day
But a new way I went to-day
Soon the walk became a shame
When dog poo was flung my way
Now all I can think is goodness, f my liiiiife.

Why was the man walking your dog in a different part of town? We need more background.

That's not relevant to the situation

Did you not read the fml? OP was walking their dog in a different part of town, not the man.

Sounds like it's time for the old flaming bag of dog poop gag.

Did you lose your pencil Richard?

He's not RichardPencil, he just appropriated my pic!

Is nothing sacred? Should have known, there is only one RichardPencil.

That was your initiation to the neighborhood.

And, for the record, I created my profile pic and others have appropriated it without permission. I am flattered nevertheless.

Maybe your dog has another owner on the side.

I would smear it all over his car... with gloves of course.