From the box:
Kitty, Puppy, Bunny and Turtle are waiting for you at the Littlest Pet Shop! You may be able to take one home if you can match its Pet card with it's matching color Pet Food or Pet Carrier card.
Once you have a match, spin to see if the Shopkeeper will let you take that pet home! First player to collect 3 pairs of matching cards and 1 pet wins!