There are a bunch of different programs you can use to make a .gif, among them GIMP and (I can only assume) Photoshop. If you have either one, there are plenty of guides on the Internet on how to animate using them. If you don't have either of them, though, you can always search online for websites that can make the .gif for you.Google is your friend. =PEDIT: Speaking of which, are full frame-by-frame animations allowed, or can we only enter .gifs in the standard comic format?