When Jesus returns to earth as the promised Messiah, He will at last usher in the dream of ages, world peace. This will involve even the whole of nature, as the world will be transformed into an Edenic paradise (compare Isaiah 51:3 Isaiah 51:3For the LORD shall comfort Zion: he will comfort all her waste places; and he will make her wilderness like Eden, and her desert like the garden of the LORD; joy and gladness shall be found therein, thanksgiving, and the voice of melody.
American King James Version×; Ezekiel 36:35 Ezekiel 36:35And they shall say, This land that was desolate is become like the garden of Eden; and the waste and desolate and ruined cities are become fenced, and are inhabited.
American King James Version×).
Indeed, Isaiah 11:6-9 Isaiah 11:6-9  The wolf also shall dwell with the lamb, and the leopard shall lie down with the kid; and the calf and the young lion and the fatted calf together; and a little child shall lead them.
 And the cow and the bear shall feed; their young ones shall lie down together: and the lion shall eat straw like the ox.
 And the sucking child shall play on the hole of the asp, and the weaned child shall put his hand on the cockatrice' den.
 They shall not hurt nor destroy in all my holy mountain: for the earth shall be full of the knowledge of the LORD, as the waters cover the sea.
American King James Version×explains that the very nature of many animals will change: "The wolf also shall dwell with the lamb, the leopard shall lie down with the young goat, the calf and the young lion and the fatling together; and a little child shall lead them. The cow and the bear shall graze; their young ones shall lie down together; and the lion shall eat straw like the ox.
"The nursing child shall play by the cobra's hole, and the weaned child shall put his hand in the viper's den. They shall not hurt nor destroy in all My holy mountain [God's Kingdom], for the earth shall be full of the knowledge of the Lord as the waters cover the sea."
Isaiah repeats part of this amazing prophecy in Isaiah 65:25 Isaiah 65:25The wolf and the lamb shall feed together, and the lion shall eat straw like the bullock: and dust shall be the serpent's meat. They shall not hurt nor destroy in all my holy mountain, said the LORD.
American King James Version×.
Fulfillment of this prophecy will require, it seems, a restructuring of the global ecosystem. But we should note that the animals mentioned here are also symbolic of nations, and their peacefully dwelling together represents an end of war among people.
The lamb, kid, calf, fatling, ox and cow often appear in Scripture to symbolize the generally peace-loving Israelite peoples. As for the great cats (leopard and lion) and the bear, Daniel 7 mentions them to symbolize great gentile empires.
These parallels are perhaps most clearly seen in Jeremiah 5:6 Jeremiah 5:6Why a lion out of the forest shall slay them, and a wolf of the evenings shall spoil them, a leopard shall watch over their cities: every one that goes out there shall be torn in pieces: because their transgressions are many, and their backslidings are increased.
American King James Version×, where the lion, wolf and leopard are widely understood to represent Israel's enemies. In God's millennial reign, God will change the wild nature of the "beasts" among men, as was figuratively portrayed by Nebuchadnezzar when God made him (the Babylonian lion; compare Daniel 2, 7) to eat grass with oxen (4:33).
Peace throughout the natural realm—and a unified human race. What a beautiful picture God has painted for us. GN