You will have to name your petling after you feed it for the first time., it can not be renamed later

Each Day the petling will ask for a different food, feed it the food it asks for

You will need to feed your pet up to 4 times in a period of 72 hours for it to become fully grown. It will only ask for food once every 24 hours so it will take 3 days from the time you bought it for each petling to become fully grown

If you delay feeding your pet for more than 24 hours, it will take longer than 72 hours for it to become an adult

The Growth of a Petling

If you keep your petling hungry for 24 hours (If you keep it with the sad eyes and food bubble for 24 hours), it will run away and you will have to hire a detective to get it back or ask your friends help.

To feed the petling open you chest and drag out the item it wants and drop it on it’s head

You can feed it something it doesn’t want but it will not grow

After you have named your pet, you can find them in your chest by typing KITTEN or PUPPY, DOG or CAT.In the future Playfish will make it possible to find it in the chest by the name you gave it

Your pet will change colours after you feed it for the first time and it will stay that colour, each petling is a different random colour

All Current Possible Colours for Dogs (except Orange):

Possible colours for Cats (missing Orange):

If your pet has a blank food dialogue it’s asking for a bone.

You can also change its colour using the biscuits in the cash shop.

(source)