Fungal Forests are the most recent addition (in regards to biomes) to the Erebus, and are quite a sight to behold.
Within Fungal Forests, you will find many kinds of Mushroom, both small and large, in addition to the infamous Glowshroom, which grows ever outward from the ceiling.
Rotten Wood can be found in this biome, spawned as hollow logs and stumps. Occasionally, these stumps can be a Jumping Spider Stump.
Moss and Mould occupy many ground, wall and roof surfaces in this biome. It is the only place to find Mould for farming, which in turn is used for the Composter as fuel. Ferns can also be found.
Fungal Forests are the only biome alongside Submerged Swamps to not spawn Botflies.
The following mobs can be found in Fungal Forests, most of which are exclusive: