I thought back to the magic portraits in the Harry Potter movies and then found a way to make them! The program CrazyTalk allows you to edit any portrait into a moving "magic" video. It takes a lot of work to make them perfect, but I started on a few and got addicted.
A free sample of an animated King Louis XVI embedded into a powerpoint slide is available for download here.
You can see the complete French Revolution powerpoint with many of these moving magic powerpoints in this video:
The actual powerpoint file with all 24 slides and 9 videos is available for purchase here. You can edit this powerpoint or use it immediately as is in your French Revolution lesson to startle your students!