How do make a virtual pet, like the ones that hatch and grow once you post them on you web page?

Those pets that they post up and have a code where you can put in html on your webpage. They hatch then grow, I want to know how to make them. Not making a pet site, just those growing creatures. Could you give me the link to a web that explains it or give me the exact instructions?

How do make a virtual pet, like the ones that hatch and grow once you post them on you web page?

You might better help if you post this question in the Games %26amp; Recreation section of Yahoo Answers since this is only for living pet animals.

Yahoo Answers%26gt;Games %26amp; Recreation.... http://answers.yahoo.com/dir/;_ylt=AhR3X...