Use the Xposed Framework or Frida to hook into the game's existing Animal class to inject new stats or behaviors.

You may need to edit the assets or res/layout files to add new buttons for things like "Mark Territory."

Permanent or long-term debuffs (limping, reduced attack) after taking massive damage from a boss.

It sounds like you're looking to modify or add a new feature to the (specifically referencing a modified version 1.2). Since this game by Gluten Free Games is an open-world animal simulation, there are several ways to expand its mechanics through modding or conceptual design.

A "Predator-Prey Hierarchy" feature would make the world feel more alive.