There are six world bosses available in the game, the first two at phase two, the latter four added later via a patch. The problem with those fights is that once they spawn everyone rushes to their location and oftentimes a lot of PvP action happens around them. They all respawn every 3-7 (random!) days to make them less predictable. The importance of those bosses cannot be estimated yet but most players probably will never face them in a raid group anyways.
- -Lord Kazzak (Blasted Lands)
The first two offer solid T1 levels of gear but especially Azuregos can be a bit of a pain to bring down because of a debuff he puts on players once they die. The four dragons of nightmare offer some decent loot, especially the nature resistance gear is really helpful when progressing into AQ40.