Portal to Yuggoth is an encounter in Conan Exiles that was added in the 3.0 Age of Sorcery update.
All encounters can be enabled and disabled at any time by Funcom and have frequently been disabled due to various issues with them.
Encounter[]
In the Exiled Lands, Portal to Yuggoth can appear at Scavenger's Berth and Eyelet Lake.
On the Isle of Siptah, it can appear at the Leyshrine of the Birdmen.
While this encounter is active, a massive blue portal with dangling tentacles can be seen in the sky from a long distance away.
Within the area of the affected camp, an eerie (and alien) hum can be heard.
Invasion[]
Egg-shaped vessels with twisting tentacles that occasionally glow with cyan light, and that emit noxious gas, will be positioned around the area.
Bug-like MiGo will also appear within bolts of energy like lightning strikes. Whenever a MiGo is slain, a replacement will appear shortly after.
Nearing the egg-like vessels will cause them to begin rapidly pulsating before bursting open to reveal dead Failed MiGoExperiments, who still appear human, or mutated successful MiGo Experiments.
Conclusion[]
Once enough MiGo have been killed, the portal will close and a final Frenzied MiGo boss will appear.
The encounter will be concluded when the Frenzied MiGo is destroyed. Any remaining vessels, Migo Experiments, and individual MiGo will also immediately die.
Loot[]
All MiGo and MiGo Experiments drop random amounts of 
Black Ice, 
Brimstone, 
Demon Blood, and 
Raw Ash.
No other unique rewards are available.