Player Mini-Me - Miniature Player Version
This mod adds a miniature copy of your character to the game, displayed in the top-left corner of the screen. You can see what your hero is doing in real time - the mini-version repeats all movements and actions.
The small figure shows your skin and all equipped armor. When the character walks, the mini-version's legs move in rhythm with the steps. Actions such as sneaking, sprint-swimming, and flying with elytra are also displayed.

Requires Fabric API and Fabric Loader. The mod is an updated version of Paper Doll, created based on the work of the original author and other developers.
Source code is available on GitHub: https://github.com/PhoenixVX/Player-Mini-Me