Cirrifog was the term applied to unique microcrystals found in Monor II's atmosphere. Thick and pearlescent, they caused the air of the world to be dangerous for most sentients to breathe—billions of the crystals could be found in any given cubic meter of atmosphere. Naturally, the Sunesi, native to Monor II, adapted to their environment; so much so, in fact, that young Sunesi would die without the cirrifog. During their metamorphosis into adults, juveniles actually used the crystals to create a sort of cocoon.