An adoptable is a drawing with the same lineart each time. Every person that gets one will have the same lineart but it will be colored differently. These adoptables are growing ones. After one week of owning one you will be given the next stage. There are three stages. Sometimes I will have random ones up for adoption others you can request. The lineart can be changed to fit your request.
(http://i47BannedImageSite/35a3km8.jpg)
These are the stages. This character is CharChar, my Fursona.