it doesnt say how big it is. But I think maybe its symbolic as 'beasts' signifying world empires in Revelation.
common emblems of world empires include predatory beasts eg
china- dragon
usa- eagle
russia -bear
britain -lion
the last beast is 'like a lamb' but speaks as a dragon, so its probably an empire that appears christian but is actually not and is evil.
The dragon is Satan.
USA is not the eagle.
Russia is not the bear.
Britain is not the lion.
Daniel had a vision of 4 beasts, kingdoms, that came one after the other, and they were different than each other which means they all had a chief mode of operation different than each other.
Which are the 4 ways of people, and even though all 4 kingdoms went by the 4 ways there was one mode of operation that was their chief mode of operation, and the other 3 a minor mode of operation, whatever that ratio was.
The first was like a lion, Babylon, and represents human religion, the occult.
It had eagle's wings for king Nebuchadnezzar acknowledged the God of Israel as the greatest god, and God blessed his kingdom.
The king's son blew it by taking the vessels out of the temple of the LORD and drinking out of them praising false gods, the so God stripped the kingdom from him, and gave it to the Medes and Persians, the eagle's wings were plucked, and they were made to stand upon the feet as a man.
Then Babylon became known as the kingdom of man.
The second was like a bear, Medo-Persia, which represents physical cruelty in war, which it says rise up and devour much flesh.
The third was like a leopard, Greece, which represents human wisdom.
The fourth is like iron, Roman Empire, and represents pushing for power, dominion, world domination.
The 4th had 10 horns which is in the future the world split in to 10 sections with a leader in each section, and the antichrist will come from the 10 horns.
The first 3 kingdoms will never have physical dominion again, but their lives were prolonged for a time and a season, which means their ways are still on earth.
The fourth beast does not lose her dominion until Jesus puts down the world, and she shall devour the whole earth, tread it down, and break it in pieces.
And even though the nations came together as one the dominion is the Roman Empire.
The beast kingdom in Revelation 13 is the kingdom of man in its entirety with all 4 chief modes of operation in that kingdom with no minor mode of operation.
Babylon will never have physical dominion again so this kingdom is Babylon in spirit, for Babylon represents the occult, human religion, and the kingdom of man, and that is what the beast kingdom is about.
The beast kingdom acknowledges no personal God.
The 10 horns are the physical dominion, Roman Empire.
With the ways of a lion, the chief mode of operation of Babylon, only going by their own religion.
With the ways of a bear, the chief mode of operation of Medo-Persia, being physically cruel in war to go against everybody that opposes them to get them off the planet.
With the ways of a leopard, the chief mode of operation of Greece, only going by their own wisdom.
The beast has 7 heads, the last 7 kingdoms, and 10 horns the physical dominion of the beast kingdon.
In Revelation 12 the crowns are on the heads, Satan in the spiritual realm deceiving people by way of those 7 kingdoms.
In chapter 13 the crowns are on the horns, Satan in the physical realm deceiving people by the antichrist, New Age Christ.