The Dr. Seuss book titled The 500 Hats of Bartholemew Cubbins lends itself well to an art activity. I used to substitute teach, and kept this book in what I called my "Substitute's Bag of Tricks". When I needed a filler quick, this worked well.
In the story, a young man tries to remove his hat for the king, but other hats keep appearing on his head, and he gets into all sorts of trouble with
the king. Near the end of the story, as he nears the 500th hat, which turns out to be the last hat, the hats start changing and becoming more fancy with every new hat on his head. I stop at this part of the story, and have everyone design hats that show how they think the last hat will look. To make the activity the most fun, I like to have lots of hands on materials: buttons, beads, fake jewels, feathers, different colored paper and streamers, etc. In a pinch, though, it is still fun to have your child draw a picture of the last hat. Then, once everyone has made a hat, finish the story.

Finally, after finishing and discussing the story, it is fun to talk with your child(ren) about how their hat was the same and different from the 500th hat.