Tesserians are known for their deep sense of caring and respect for others. They have a love of order and peace and a need to be connected with others.

Pale skinned, with large eyes, fragile builds and "alien"-like oval heads, Tesserians are everything humans expected to find in outer space.

The Story of the collapse of Tesser:

Tesser is the 11th of the creator's twelve worlds and closest to Earth. Using ancient religious texts from three other inhabited planets as guides, Believers first charted the location of the planet Tesser and arrived to find its great cities vacant.

The communal Tesserians were the first to achieve interstellar travel. But the planet had a limited supply of Tritium for fusion, and an energy crisis brought the harmonious Tesserian civilization to the brink of collapse. Seeking access to Earth's massive supply of nuclear fuels, Tesser launched a desperate mission to reach humans who were just taking their first steps into space. After a secretive first contact, a large supply of US-made Plutonium was sent back with the Tesserian ship. But the gift came with a price. An outbreak of Earth-borne viruses on Tesser brought the peaceful civilization to a grim end. The planet's spectacular cities and skylines are but gravestones.

Relics of Tesser technology have been found in Believer space systems. However, the full extent to which Believers benefited from Tesser technology is not known as the Believer fleet avoided a full-scale conflict with ASP at Avalon following the extermination order and instead fled to Xahna.