There is definitely a lot of similarity between Rocky and the puppies. I can see two spots on Rocky's tail, and so I was looking for a puppy that had them in the same spot.

If you look at the puppy below that is kind of hidden next to his mom with the two brown spots on the base of his tail...


...and then you compare the placement of the spots with this picture of Rocky, I definitely see a lot of similarity.


Too bad you don't have a full body shot of the puppies...