Satan

[Dawid]

The book of ezekiel, chapter 28, verses 11-19, talk about lucifer, the fallen angel_
verse 13- ..you were in eden , the garden of God
verse 14-you were the anointed cherub who covers
werse 15-you were perfect in your ways from the day that you were created till iniquity was found in you

Actually, this is referring to the king of Tyre (cf verses 2 and 11)
Now, I agree that the New Testament talks about demons, etc. What I think we were saying is that these concepts were not fully developed in the Hebrew Bible. There was certainly some concept of "the adversary" in Job, but this is not clearly the same as the concept of the "tempter" which had developed in the intertestamental period.
Secondly, I don't think that the New Testament ever says that they're fallen angels. That's a later postbiblical idea.