There are likely too many to create a reasonably sized GIF file.
Here they are:
http://www.disneyonlineworlds.com/index.php/POTCO_Hints
If you set a background color for your image like black for example, it should remove the blue bars, which could also be made "transparent".
If I were doing this, I would import the full loading screen for each and every hint FIRST (each frame would be a full loading screen) (might save a copy of the original to use do add)
Then crop the image so it would accomodate the hint text for all screens. Much more consistent aesthetic animation.