onyxa, its like 2 months necro here ^^
Actually, ask several people reported already, there is 12 Onyx Eggs spawning at a time, with unknown CD, but more likely around 1h hour.
Me personally have found max 11x in 5min timeframe on a dead server. By dead I mean having ~40-45characters online in sunday evening on each side Alliance / Horde, and most of them are not even 90!!
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