The Bible will tell you when there is a poem, or prayer, or a metaphor. I believe that every one knows that when the Bible says that God is our "ROCK" it does not mean literally that he is some kind of hard round stone. We understand the logic and the use of a word to symbolize the meaning the writer had in mind.
So then in Rev. 12:4 and anyone is welcome to disagree with me by the way, it seems to me that the "tail" symbolizes the delusive power of Isaiah 9:15.....................
"The ancient and honerable he is the head, and the prophet that teacheth lies, he is the "TAIL".
That tells us that Satan used his power to accomplish the moral ruin of those in high positions. But he is not successful with all, only a third.