Animated cartoon while a user waits on our website

Our web application has an analytics feature we call 'insights'. It takes work that students have done, and provides an overview/trend data to the teacher. When a teacher accesses some old data for the first time, we have to do some number crunching to make it happen. This can take up to 20 seconds. To keep them amused, we'd would like to show them a little animated gif loop while they wait. Please see the attached sketch, but I am open to other suggestions. Have also attached a screenshot of the screen that eventually will render in once we've finished our number crunching, so you have some idea of our style.