13:1 The dragon[a] stood on the shore of the sea. And I saw a beast coming out of the sea. It had ten horns and seven heads, with ten crowns on its horns, and on each head a blasphemous name.

The dragon[a] stood on the shore of the sea.

This sentence according to the best old manuscripts belongs with the last verse of the previous chapter. The dragon (devil) is contemplating his next move.

And I saw a beast coming out of the sea.

While this may be a literal sea creature ugly as it is described, the most likely interpretation is that a demonic leader will come up from the "container of evil spirits", the SEA. The description of SEA in Revelation 17:15 would also indicate that the SEA means someone from among the world's nations.

Some manuscripts And I