I don't know what he is, but he looks like my dog, Spanky. I don't know what Spanky is either. Spanky was listed as a Terrier/Hound mix at the pound. Looking at him, you can see the terrier, but I'm not sure where they got the hound except that they thought they knew who the father of his litter was, and maybe he was a hound of some sort.
I will try to post a picture of Spanky soon.
Spanky also has a striking resemblance to the Petit Bassett Griffon which is a hound. Since it's a relatively rare breed, I don't think Spanky's mixed with that, I think it's just coincidence that he looks like that. And, there's a bearded collie at the facility that he boards at, and he looks like he could have bearded collie in him.