You might want to try the free game Minetest [1]. It is very similar to Minecraft but the basic version, minetest_game, has no animals. You can add mods that give you animals if you want them but they are not necessary. There are hundreds of open source mods to choose from or you can write your own mods in Lua. I learned Lua by examining the mods that come with the game and changing them. You can play in a mode where you can't take any damage. Multiplayer games can enable or disable PvP.
[1] http://minetest.net