Revelation 12:3

3Then another sign appeared in heaven: and behold, a great red dragon having seven heads and ten horns, and on his heads were seven crowns.

3Then another sign [of warning] was seen in heaven: behold, a great fiery red dragon (Satan) with 12:3 The seven heads and ten horns correspond to the heads and horns of the beast in 17:3 ff, and to those of the beast in Dan 7:7 ff as well. Daniel’s description reveals that the ten horns are ten kings who temporarily reign with the Antichrist during the Great Tribulation (cf 17:12).seven heads and ten horns, and on his heads were seven royal crowns (diadems). [Dan 7:7]