Revelation 16:12-16 ESV
The sixth angel poured out his bowl on the great river Euphrates, and its water was dried up, to prepare the way for the kings from the east. And I saw, coming out of the mouth of the dragon and out of the mouth of the beast and out of the mouth of the false prophet, three unclean spirits like frogs. For they are demonic spirits, performing signs, who go abroad to the kings of the whole world, to assemble them for battle on the great day of God the Almighty. (“Behold, I am coming like a thief! Blessed is the one who stays awake, keeping his garments on, that he may not go about naked and be seen exposed!”) And they assembled them at the place that in Hebrew is called Armageddon.
ESV: English Standard Version 2016