Today, on the eighteenth day of June in the year of our lord 2014, Twitter finally decided to support GIFs.
Yes, it's true. The next time you tweet something out, simply upload a GIF file as you would any other picture, and it will display in the post. Though, GIFs won't play automatically: you'll have to press play on the file in order for it to start looping, but it's better than nothing.
Head to Giphy or do a Google search for animated images to find some cool GIFs to upload.
Check it out:
