Kalderans are robust bipeds with an average height slightly taller than a human, but significantly lighter due to hollow bones and a more gracile build. Though descended from flightless, featherless avians, Kalderans have a more reptilian appearance, with elongated heads and fragile, photosensitive eyes that are often shielded using glasses or goggles.
Kalderans have two genders, with the female typically laying one to two eggs per cycle. And much like Earth's emperor penguins, the male typically stays with the egg until hatching, a process which takes between 150 and 175 days. As befits their collectivist culture, many Kalderans participate in the rearing of young, who still maintain relationships with both parents well into adulthood.
The Kalderan homeworld is Kalderash, a pleasant world in the lesser Magellanic Cloud that's nonetheless experienced great hardship throughout its history. (see Timeline) The majority of Kalderans prefer to live on Kalderash, though significant colonies, outposts and garrisons can be found throughout both Magellanic Clouds, mainly on worlds controlled by the Kalderan Commune.
Socially, the Kalderans are a very contradictory species. Among themselves, Kalderans are radically democratic, almost to the point of chaos. Kalderan society is organized from the bottom up along roughly anarcho-syndicalist lines, with small numbers organizing themselves into so-called affinity groups, a dozen or more affinity groups making up local councils or soviets, and so on up to the governing Commune itself (see: Kalderan Commune). Nearly every decision is arrived at through consensus among -a process which would be paralyzing to most other species, but seems to work well for the Kalderans.
Unfortunately, this Kalderan love for democracy no longer extends to other species. Since the fall of the Commonwealth, the Kalderans have undertaken a vigorous campaign of conquest over their region of space, ruling firmly over their territories and ruthlessly crushing rival political entities. Some scholars theorize that this double standard relates to the ancient trauma suffered by the Kalderans after they were conquered and nearly exterminated by the Vedrans ten centuries ago, but this is cold comfort to others who find themselves chafing under Kalderan rule.