1. Progress Through the Grim Tangle Zone
Exploration: Fungal Boss Events are primarily located in the Grim Tangle zone, which is a region filled with POE2 Currency toxic landscapes, fungus-infested forests, and spore-based enemies.
Unlocking the Region: You must first progress through the main campaign and reach the Grim Tangle area. This zone is typically unlocked after completing earlier campaign stages. The fungal bosses you seek will be found scattered throughout this region.
Event Activation: Some Fungal Boss Events will be triggered as you explore, while others will require you to activate them by completing certain quests or actions.
2. Triggering Fungal Boss Events
There are various ways to trigger these events in the Grim Tangle zone:

Random Spawn: Some fungal bosses will randomly spawn as you explore specific sections of the zone. Keep an eye out for notifications or quest markers that indicate a fungal-themed boss event.
Quest-Related: Certain side quests or activities related to the fungal infection storyline will unlock these bosses. Completing objectives such as defeating certain spore-enemies or clearing areas will prompt special fungal boss encounters.
Fungal Essence: After collecting enough Fungal Essence from creatures within the Grim Tangle, you will be able to activate boss events. Look for fungus-infested altars or cursed stone shrines in the area that require these essences to summon the bosses.
Group Events: Some of the more powerful fungal bosses can only be triggered in group events or special challenges. These events will require a team to defeat the boss, but they offer higher rewards.
3. Defeat Specific World Bosses or Mini-Bosses
World Bosses: Some world bosses in the Grim Tangle are exclusive fungal events that can spawn as part of a special event. These events can happen in random locations within the zone and require group participation to complete.
Mini-Boss Encounters: There are mini-bosses within the Grim Tangle zone that, when defeated, will unlock fungal boss events. These encounters are tied to specific quests and puzzle-solving mechanics within the region.
4. Specific Bosses and Event Requirements
Certain fungal bosses require specific conditions to trigger, such as:

The Fungus King: This boss can spawn randomly after defeating other fungal-infested mini-bosses in the area. You must also have a high Fungal Essence count.
Mycelium Overlord: Triggered by defeating spore-covered creatures and completing quests that delve into the core infection of the Grim Tangle. This boss can offer rare crafting materials and fungal-themed loot.
Spore Lord: The Spore Lord is often unlocked through side objectives in the Grim Tangle. These could involve collecting spore clusters and toxic remnants scattered throughout the region.
5. Fungal Boss Event Rewards
These events often offer special rewards and materials necessary to buy POE 2 Currency craft chaos-infused gear, potions, and other powerful items in the Vile Alchemist’s Workshop. Some key rewards include: