Aesop is Scout's companion and beast of burden. He is first seen in the beginning of the game meeting Scout, and though he’s not much use in a scrap, he can carry supplies, call out clues and warnings, and generally help you navigate the wilderness.
Items in Aesop's bag will carry over to your New Game when you DIE. If you make a new game without dying or "continue" after a death then decide to start a New Game, Aesop's bag will not persist. You'll need to die again in the Continued game or New Game.
You can turn On/Off bag persistence in the options menu if you would like to make it more challenging.