View Can You Make A Gif Your Background PNG. You can pick an animated gif in many ways. Export gif's with a transparent background using adobe after effects and photoshop.
I use aoao video to gif converter to make my own gifs. This animation maker works on windows, mac and linux, the only thing. Use upload to add your gifs and creations to giphy so that you can share your gifs on hit the create gif button to finish.
If by saying gif you mean moving picture, you can't do it traditionally.
Use the url field to point it to a source for a gif. How to make a gif with photoshop. Upload and edit gifs, share everywhere. Animated gifs tend to get annoying pretty fast and you might be alienating followers who would otherwise come to your twitter page.