This from John Goldingay’s book “Genesis for Everyone (Part 1),
Genesis was concerned about plants and trees as sources of food. God now gives the plants and the fruit trees to humanity to eat and also give to the rest of the animal world all the other plants, the ones human beings don’t eat. The shocking implication is that both humanity and the rest of the animate world were designed to be vegetarian. It is only after humanity has become disobedient to God that it eats meat; in the time of Noah, God then agrees to this (Genesis 9:1-3). But at the time of creation, the thought of humanity eating meat was no in God’s mind. So much for the idea that humanity is free to do what it likes with the world, to treat it as belonging to us, available for our exploitation. We were not even free to eat the animals we were put in charge of. So people who do not eat meat are witnessing to an aspect of God’s actual creation intent, whether they realize it or not.” p. 20.
These seems to be confirmed by the verses he cites
“Then God blessed Noah and his sons, saying to them, “Be fruitful and increase in number and fill the earth. 2 The fear and dread of you will fall on all the beasts of the earth, and on all the birds in the sky, on every creature that moves along the ground, and on all the fish in the sea; they are given into your hands. 3 Everything that lives and moves about will be food for you. Just as I gave you the green plants, I now give you everything.” – Genesis 9:1-3
Have you ever considered this? It is obviously no longer the case today but I had assumed that rule and subdue the earth implied killing and eating of animals. That means there were definitely no prediluvian unicorn beast feasts. Bummer.