Originally Posted by
0nionKn1ght
Much like when monsters despawn in Abyssea to reset their levels, when daddy shows up, the kids hide until 5 minutes after the last death of the big one. Could even take it further, for example:
The setting: Dragon's Aery
The target: Nidhogg
Creatures found: Ancient Lizards (normal Lizard family monsters)
Kill enough Ancient Lizards (0% drop on key item drops) to spawn Hulking Ancient Lizards (0.01% drop chance on key item drops)
Kill enough HAL's to spawn Wyverns (1% chance to drop key items)
Kill enough Wyverns to spawn Fafnir (claimed to last alliance kill), causing every other monster in the Aery to despawn
Fafnir dying can occasionally summon Nidhogg (claimed to alliance that killed Fafnir) however it could be based on a chat log message "An earth shaking screech is heard from the clouds as Fafnir falls, something big is coming..." telling the alliance that in 60 seconds, Nidhogg is going to pop, and if not "The air falls silent once more as Fafnir screeches, and falls to the ground".
5 minutes after death of Wyrm, Ancient Lizards spawn again.
As well as anger spawning, you can also get the key items to lure them out early, but low drop rate from creatures in that zone, only increasing as you spawn the higher tiers.