Weird Fungus is an odd pink material that can be found in the Fungal Caverns. It can be easily walked through, although it does not provide air and can cause suffocation if one remains inside it for too long.
Unlike most materials, it will slowly grow upwards, forming usually slender columns. If a moderate amount falls down due to the ground beneath it being destroyed, the movement seems to accelerate its growth, quickly generating massive spires of pink fungus.
If ingested, the player will receive the Tripping status effect, which will cause visual distortions. If further amounts are ingested, the visual distortions can increase, and at high levels of the Tripping status, strange eyes will open and close at random in the background, with an accompanying sound effect.
When gaining at least 180 seconds of the Tripping status effect, a Fungal Reality Shift will occur.
Green Fungus is a rarer variant of Mystery Fungus, and behaves in a very similar fashion.
Mystery Fungus behaves very similarly to Weird Fungus, including the effect of ingesting it, with the additional quirk that it will convert many other liquids and powders into more of itself quite rapidly.
Blue Fungus is a static variant of fungus, mainly present as a portion of the terrain in the Fungal Caverns. As it is a static material, it cannot be ingested, unlike other kinds of fungus.