Preschool and Kindergarten Art Sub Plans
Take a look at the illustration from the book.
The original lesson has students using paint. Paint wouldn't be a medium you should leave for a sub unless you know the capabilities of the sub, but crayons will work nicely. Students will love hearing the storybook read to them. Likely, it will be a favorite. So, let your sub read that book to your students and then have the students draw their own dog party.
Read "Collage Mama's" blog post for more ideas on this lesson.