Completely obsessed with a religious concept known only as 'Juffo-wup', it is difficult to have a coherent conversation with any member of the Mycon species without it degenerating into nonsensical rambling totally unrelated to the topic at hand. While usually a Mycon will speak incessantly about Juffo-wup, another disturbing outcome would be to hear the dying thoughts of a previous generation of Mycon, behaving as if possessed by a ghost describing how it died.
Mycon see the universe as one of the three things: The 'Void', the 'Non', and the 'Juffo-wup'. While it is difficult to confirm what exactly a 'Juffo-wup' is, they consider other races to be 'non-Juffo-wup', or simply 'Non', and they will try to either kill them to turn it into Void, or become Juffo-wup. They allied themselves with the powerful Ur-Quan Hierarchy because their beliefs allow them to accept that there are creatures that cannot be 'voided' until a weakness has been found.
One of their most prized and sacred possessions is the Sun Device, a Precursor-made machine that can generate enough heat to warm up planets too cold for Mycon spores to survive and thrive.
According to the Umgah, who managed to capture and dissect a Mycon, this race of fungi is in fact artifical and was created by the Precursors to serve as organic terraforming tools. Unfortunately, their programming has been corrupted after centuries of neglect, and resulted in the bizarre religion of 'Juffo-wup'.