Below is the short clip of an octopus swimming in water.
The first step was to take the single layer image into photoshop and use the content-aware fill tool to separate the octopus from the ocean. Then it was brought into After Effects and pins were placed to add movement into the image. If I spent more time on this, I would have offset the keyframes so all the movements didn’t happen at the same time. Also, I could’ve started and stopped the movements on the same keyframe to make it appear as a fluid motion when it’s on loop.