I cannot teach you how to make Twibbles. But I can show you how to use these open source scripts to make a set of the original XS Quails.
Once you have mastered this step, you can change the scripts and objects to make your own virtual pets.
I am also releasing a set of sculpts and instructions to make saleable food, and also a set of sculpts for a 1-prim bird feeder that the birds will stay nearby :
There are many parts to this project, and I rate it as a difficult project for anyone to do. My goal is to make this a complete and easy to do project, but it is Not Quite There Yet. This uses a lot of objects and scripts inside objects and redendant copies of objects inside those objects, and my work is not complete. There are several unknown spots : what some of the parts really do; documenting and testing how all this interacts; and actually raising a few birds that can take a few weeks to hatch eggs, watch them breed with each other, and raise their own brood. It is going to still take some more work.
So I need your help! Please, if you have an XS Pet Quail, or you have tried and built this project, please comment here so that others can benefit from your experiences. If you have photos or dimensional data on any of the other parts, or any documentation, please email them to fred @ mitsi.com and I will post the pictures and credits.