Imperiumboletus

"A brain-controlling fungus, which is devastating habitats in its path of where it originally evolved. Infection is indicated from a decomposed appearance, several bulging patches of fungi, and one fungus growing out of the head region in trilobite-like animals, on various spots on the sides in sponges, and it is likely to evolve species specialized for more types of animals. It enters through inhalation. Specialize against this quickly, because the Fungal Jungle is growing."

-Toomyx

Hosts
List of creatures able to get infected:

Kleptothule

Tricuniculus (EXTINCT)

Hazelia

Terrestrialslug

Trivia
Imperiumboletus evolves into Terresfungus and Fungus Tree in Gen 4.