The Idea:

House box that the felted stuffy is inside. There are simple instructions to remove a specially made sticker on the outside of the house and pull a string, which will unfold the house, revealing the stuffy and a personalized sticker for the stuffy sitting inside the house. It would also be fun if the little stuffies came with an adoption sticker (maybe just a slip of paper) saying that whoever opened the box/house was officially the parent/guardian of the stuffy. 

Materials:

We could have the house be laser cut out of cardboard. It should have little ridges in the sides of it so all the walls click into each other like a puzzle. Then, it will be sealed with the sticker. We will also attach a string that is connected to all the walls so when you remove the sticker and there's nothing holding the house together, you will pull the string and the house will unfold, revealing the stuffy and sticker inside.