I have been making my own pixel art for every game that I create for over ten years. I have done lots of research and taken many online classes in digital art and pixel art, and create every sprite from scratch, including animation rigs and even full frame by frame animations. For the Angler fish that I used within my swimming survival game, I wanted there to be snake like movement for the body, which required procedural animation. The rig I created (through the pixel art IDE Aseprite) was made to have seperated body parts in order for them to be connected and moved through code. The sprite rig is given below: