Oh, animals would be good. Here are my suggestions:
I would suggest wild dogs, and tamed dogs that follow you around.
Animals can be killed by shooting them with a gun.
There could also be a option in the server settings, that allows animals to naturally spawn.
There could also be ragdoll animals!
And also a comment on this game, it’s mostly better than most sandbox games, it has things that the others don’t have.
Building system, furniture, and more.
Keep up the good work!