Keynote 6.0 - How to add animated gif?
Solution 1:
If you change the extension to .mov then drag it over, it’ll ask you to optimize for iOS, at which point it will treat the GIF as a movie.
Solution 2:
In my experience, animated GIFs (and Flash animations) are no longer supported in Keynote. You would probably have to use ffmpeg or QTPro to convert the GIFs to movie files and re-import them.
Solution 3:
The problem was fixed in Keynote v6.2. Update Keynote and it should work. (as mislav informed me in the comments)