I decided to animate the blue whale swimming below the iceberg. This shot is only 24 frames in duration, so that involved doing just 12 drawings. I just animated the tail swiping downward and kept the whale in place. I then exported that animation with a green screen and imported the animation into After Effects. That is where I then moved the whale forward.
At first I animated a full sweep of the tail but realized that for 24 frames the tail moved far too fast for such a huge lumbering creature. I ended up throwing out much of the animation and only sweeping the tail for about one eight of the movement.
When the shot plays in Premiere pro what is noticed is just a slight forward movement of the whale. I probably could have gotten away with just drifting the whale forward without the tail movement. Maybe on the big screen some will notice the tail move.
The tail was a separate layer and I tried to paint it to blend with the existing painting of the whale. The tail paint tends to flicker and crawl a bit so I also painted the highlights across the back of the whale to there is some flickering of light on the whales back. This made it look like the light was flickering because of the ocean waves above.
Today I will be animating a dozen people running through Times Square that scene will take days to complete.