Satan. See Rev 12:9. The word is found only in Revelation. In the Septuagint, of the serpent into which Moses' rod was changed. In Isa 27:1; Eze 29:3, of the crocodile or leviathan of Job 41:1. In Jer 51:34, of a dragon.
Crowns (διαδήματα)
The Kingly crown, not the chaplet (στέφανος). See on Rev 2:10