Here are a few sites that you may find useful for Puppy Surprise:

Ghost of the Doll, toy ID

This site is great for ID'ing many 80's toys, and shows a decent collection of Surprise animals.

The My Little Pony Arena

A forum dedicated to My Little Pony. You can also sell, buy and trade ponies and other toys here.

The My Little Pony Trading Post

Another forum dedicated to My Little Pony. This one has a much larger selling and buying base than the Arena. I have gotten a lot of my animals from here.

A site for identifying Vintage Littlest Pet Shop animals.