What always struck me as odd in the books is that although the term ''Dragon'' is widely used and known throughout Randland, the actual beasts--the dragons--are never referred to and/or described.
If you think about it, aren't dragons simply big serpents? ''Beyond the horizon, hidden fires swell, and serpents nestle in the bosom.''
In my humble opinion, when RJ says ''Beyond the horizon'' he means Shara, the vast stretch of land east of the Aiel Waste, and when he writes ''Serpents'', it means dragons.
Shara is the only place in Randland that retains a certain sense of mystery. We don't really know what's going on there except for a few peddlers stories and what the Aiel say about them.I don't think he means the Seanchan continent when he writes ''Beyond the horizon''. If so, the Seanchan armies would be riding Dragons to retake Randland.
Further evidence of this possibility comes at the beginning of CoS.
The prophecy states: ''He calls upon...the very sky to bow.'' In my opinion, another indication that dragons exist, and that they will serve Rand, the DRAGON Reborn, as TG draws near. Another prophecy in tFoH states that: ''Storms rumble beyond the horizon, and the fires of heaven purge the earth.''
Beyond the horizon= Shara
Fires of heaven=dragons
The dragons are awakening in Shara, and purging the earth as they do so.