Laguna fungus was a native organism on Laguna 9. If Terran/Lagunans did not regularly inhale droth, they would break out in fungal growth, which would kill them. It was a Terran blockade of Laguna 7, where droth was manufactured, that led to the Terran/Lagunan mass death at the end of the Laguna Wars due to fatal pandemics of fungus. The fungus was apparently not contagious.
Behind the ScenesEdit
The name of the fungus is conjecture.