Non human companions that need “training” to be effective in fights and have benefits to moral and assist in zombie grapples and other attack. Some animals like bears and wolf could act like enemies and attack players and their companions or even other enclaves. Animals like deer and elk or cows or pigs would act as a way to hunt for small amounts of food stockpiles and maybe even be domesticated for a farm or builder settlement but make a lot of noise so wild animals and zombies attacks become more frequent. This could keep players playing the game for it’s a big addition and could also bring home new people. Since people love dogs and animals and a more living breathing world, I believe a lot of people would love this addition.