Although the GIF specification doesn't state that animations have explicit comments, by placing a comment block after all frame definitions, editing applications usually display that comment with the animation. Gif Animator allows you to view and edit such comments.
Comments are not displayed in the animation, and cannot normally be viewed unless the application decoding the GIF file supports them. As comments also increase file size, they should be used sparingly. The Gif Animator Command Line Client tool has an option for removing all comments from an animation.