Humans have had no contact with the Kr'Thak. What is known to the UEE about the Kr'Thak comes only from the Xi'An. The Xi'An and Kr'Thak have been enemies for seven hundred years and for the UEE to try and make contact with their allies' enemy is not viewed as a bright political move.
They are a space-faring, nomadic race that own several solar systems, but migrate around them.
Chris Roberts resolved the mystery surrounding the name of the race (Krell vs. Kr'Thak) on Friday March 8, 2013:
|“||The Krell System is where the Kr'Thak come from. [...] Maybe you would call them the Krell, because they came from the Krell system, but their proper name is the Kr'Thak.||”|
Unknown. However, the UEE Senate has recently begun official discussion on whether or not to attempt to establish diplomatic relations with the Kr'Thak.
The Xi'An emperor has been quoted stating the Kr'Thak are an enemy of the Xi'An. The Kr'Thak have a long history of war with the Xi'An. This conflict, known as the Spirit Wars, has lasted centuries.