{Another sign} (allo s(886d)eion). "A second tableau following
close upon the first and inseparable from it" (Swete). {And
behold} (kai idou). As often ( 4:1  6:2,5,8 , etc.). {A great
red dragon} (drak(936e) megas purros). Homer uses this old word
(probably from derkomai, to see clearly) for a great monster
with three heads coiled like a serpent that ate poisonous herbs.
The word occurs also in Hesiod, Pindar, Eschylus. The Babylonians
feared a seven-headed hydra and Typhon was the Egyptian dragon
who persecuted Osiris. One wonders if these and the Chinese
dragons are not race memories of conflicts with the diplodocus
and like monsters before their disappearance. Charles notes in
the O.T. this monster as the chief enemy of God under such title
as Rahab ( Isa 51:9f.  Job 26:12f. ), Behemoth ( Job 40:15-24 ),
Leviathan ( Isa 27:1 ), the Serpent ( Am 9:2ff. ). In  Ps 74:13 
we read of "the heads of the dragons." On purros (red) see
 6:4 . Here ( 12:9 ) and in  20:2  the great dragon is identified
with Satan. See  Da 7  for many of the items here, like the ten
horns ( Da 7:7 ) and hurling the stars ( Da 8:10 ). The word
occurs in the Apocalypse alone in the N.T. {Seven diadems}
(hepta diad(886d)ata). Old word from diade(935c) (to bind around), the
blue band marked with white with which Persian kings used to bind
on the tiara, so a royal crown in contrast with stephanos
(chaplet or wreath like the Latin _corona_ as in  2:10 ), in N.T.
only here,  13:1  19:12 . If Christ as Conqueror has "many
diadems," it is not strange that Satan should wear seven (ten in
 13:1 ).