Revelation 9:11
King James Version
And they had a king over them, which is the angel of the bottomless pit, whose name in the Hebrew tongue is Abaddon, but in the Greek tongue hath his name Apollyon.
Revelation 9:11 in context
And they had breastplates, as it were breastplates of iron; and the sound of their wings was as the sound of chariots of many horses running to battle.
And they had tails like unto scorpions, and there were stings in their tails: and their power was to hurt men five months.
And they had a king over them, which is the angel of the bottomless pit, whose name in the Hebrew tongue is Abaddon, but in the Greek tongue hath his name Apollyon.
One woe is past; and, behold, there come two woes more hereafter.
And the sixth angel sounded, and I heard a voice from the four horns of the golden altar which is before God,