There could be character analysis. For example, worksheets might ask students to describe Buck's transformation throughout the story.
The worksheets may also include activities related to the visual elements of the graphic novel. Maybe questions about how the illustrations enhance the mood of the story. For example, the use of dark colors during the more dangerous parts of Buck's journey could be a point of discussion. They might also ask students to compare and contrast the graphic novel version with the original text in terms of how the story is presented visually.