Premium accounts have the ability to upload animated avatars immediately after the account is created or converted from a basic account!
For other accounts, Animated avatars cannot be uploaded unless you have purchased at least 5 site tool points. You can purchase tool points on this page.
Other site users may donate the ability to have an animated avatar to you, if they so choose. They do that from here.
You will maintain the ability to have animated avatars regardless of what your tool point balance is. In other words, if you use your tool points, and your balance goes below 5, you can still have animated avatars. A Premium member will retain an animated avatar even with a zero tool point balance.
All animated avatars must be 8k (8192 bytes) or smaller in size. If a larger file is uploaded, the animation will be stripped.
Visit the terrific folks in the Avatar Forum to get help with your avatar design.
NOTE: Some users who previously had animated avatars seem to have lost that capability during a recent change to the system. There is a thread that explains some of that here: /forum/remark,5554743~root=fallen~mode=flat