How to implement customization of pixel characters?

Question

Game development

Let's say: there is an animated character sprite, what are the options for imposing things on it and automatically animating them depending on the character's animation? Is it even possible? Frankly speaking, I know little in this area, I want to at least know in which direction to dig.

Answer 1

Put things on the top layer. Dig in this direction.
Well, or "on the forehead" - generate a bunch of animations with different things.