Because even in the Bible, the dangerous and ferocious creature Leviathan was created by God according to Psalm 104:24-26. Plus, according to science, there are other dangerous and ferocious creatures that God created such as sharks.
However, if that was too long for you, I have this 51 second video, which features characteristics that only a Creator God could create. (Hebrews 3:4 and Revelation 4:11)
Therefore, are the scriptures that mention total peace in the human kingdom and the animal kingdom only referring to land creatures? And do those verses exclude the sea creatures? Because I don't quite get it.
But here is another example of the electric eel in this 2 minute and 25 second video, even though there are many, many more dangerous and predatory sea creatures such as this.