Foreground and background
A nine frame animation loop with addition of foreground and background, as well as control over frames-per-second.
Use the top nine frames to draw your animation frames. Draw a static background frame in the bottom-right region. Your animation will be layered over this background by turning all white areas of each animation frame to transparent. Draw a static foreground in the bottom-left region. What you draw here will be layered over your animation, turning white areas of the foreground to transparent.
This animation grid defaults to 12 frames-per-second, but you can override that value by using a dark color to fill in square of new FPS value you desire.