The Orz are newcomers to TrueSpace, that have suddenly appeared out of nowhere in the vicinity of Vulpeculae constallation. They are water-breathers who resemble yellow parrot-fishes, though it is not known if this is their actual true form.
Orz seem to come from another dimension, which is not QuasiSpace as the Arilou tell. Arilou say that they are from "above" and the Orz are from "below". There has been some discussion if the Fish-Orz are actually projections of some higher being studying our reality, but these are only theories.
Translating Orz speech is problematic at best. Even the most sophisticated and powerful Translators can't fully translate their bizarre alien language, having to use many lingual best-fits in conversation.
The Androsynth once lived in the Vulpeculae stars, but vanished about the same time Orz arrived. It is reasonable to think that the Orz did something to them, but asking about it from the Orz always seem to infuriate them totally.