The Pet Buddy mod makes a miniature version of yourself and it follows you around wherever you go. If you don’t see it at first just press P and it should appear at your feet.
It doesn’t do much until you give it a chest. Then it has the capability to pick things up for you on your journeys. It can hold up to 12 items at a time.
You can also give it a helmet and a sword so it can be somewhat protected but also fights for you.
And if it gets injured just feed it anything you would eat and it should heal right up.
And a neat little feature is you can change the way it looks by putting a certain item in the bottom box of its menu when you right-click. It’ll change into various mobs in the game with items like chicken for a chicken, wool for sheep, or cookies for bats! Plus there many other combinations to be had just check the wiki for more information.