FOSTER NEEDED before PAWS catches him!

Muppet has been living on the loose in a neighborhood; PAWS has been trying to catch him, but the neighbors like him & have been helping him out :)  We're guessing he is a shepherd / retriever / chow mix...purebred mutt.
He is very scared right now & needs someone who is patient & willing to work with him.  He is good with kids & other dogs, but he is a climber.  He did scratch a runner, but, they were running.  He is cautious, so he needs a relaxed meeting...but warms up quickly when he realizes you aren't going to try to take him to the pound!