Mon Calamari Nerveshock was a fatal disease that affected Mon Calamari on the planet Dac. It could remain dormant in its host for several years as the host aged. When it finally became active, it was already too late to save the victim. Rapid degeneration of the nervous system was the primary result of the virus, which eventually left the Mon Calamari unable to survive. For these reasons, all Mon Calamari children were immunized against it.