For practical reasons, I’d have to say a cow. I have an automatic cow farm in my survival world and it’s amazzzing. I never have to worry about food with it, and steak keeps your hunger down longer than other foods. I used to rely on bread since I have a huge wheat farm but your hunger goes down pretty quickly which is unfortunate. Otherwise I’d say a wolf. I love having dogs in my survival world, they’re fun to have around.