This is a minecraft mod I have been working on that adds an entity. This entity's goal is to kill the player and as the game goes on and the player interacts with and kills this entity more, it will adapt to the player's strategies to better combat them.
Right now, the entity will follow the player, breaking blocks if needed, and will try and kill them with normal punches.
I plan to eventually have the entity gain certain set power increases (like armor and damage and movement speed) when the player reaches certain acheivements in the game.