When the Soviet Air Force Space Division probe Almaty-15 didn't return to Earth from its mission to what would be later known as the Brabant system, tensions increased even more between the American Empire and the USSR. The Soviets sent a task force to deal with the problem with one simple order: determine what happened to the probe. In this regard, the task force was successful.
The osminogi are one of the many xeno species that mankind has driven to extinction, or very nearly so, in its expansion across the stars. Although most of these species were exterminated through sheer callousness and apathy, having their homeworlds terraformed with complete disregard to any life on them, the osminogi are special in that they are one of the few pre-Collapse xenos to be exterminated for posing a threat to humanity itself.
The osminogi were named as such by the Soviet task force sent to investigate Almaty-15 for their superficial similarity to the octopus (osminogi being the Russian word for octopus), but unlike their namesake they are vertebrates (albeit with carbon-based skeletons), rely on infrasonic hearing as opposed to sight for spatial perception, rely on a thick covering of poisonous fuzz to protect themselves from predators, have six "tentacles" lined up along a cylindrical body instead of eight more or less radiating outward from a single "head," and move in a way closer to Terran monkeys and worms than anything aquatic.
It is well-known that the osminogi were, like all sapient species mankind has encountered, prone to war. The osminogi were in the middle of a global war during the 2180s, an industrial one similar to humanity's Great War but on a much larger scale. The heavily industrialized powers of Brabant V (the osminogi homeworld) were more evenly split among three ideologically-motivated alliances, resulting in massive casualties on all sides. The three alliances only put aside their differences in the face of the Soviet attack, but by that point it was too late.
Osminogi technology, from what little there could be determined after the Soviet attack and the Collapse, was several centuries behind mainstream mankind before first contact. Almaty-15 was shot down by a rocket-based anti-aircraft weapon, indicating a technological awareness similar to that of Great War-era mankind. However, analysis of ruins of Brabant V indicate a knowledge of transistors, which humanity itself was only beginning to master during first contact, but absolutely no awareness of nuclear technology or even the possibility of weapons of such scale. This could take into account the widespread, almost supernatural fear the osminogi experienced during the Soviet bombardment.
The bombardment itself continues to be a controversial, especially with regard to the motivation behind it. Vitaliy Afanasyev, the Soviet commander of the task force, justified his decision by calling the osminogi a threat to the Soviet Union and mankind as a whole. He argued that the remains of Almaty-15 could easily be reverse-engineered by osminogi scientists and that he was saving humanity from a violent species. He also cited Soviet doctrine at the time, which similar to American and German policies called for "prudent suspicion" when it came to dealing with extraterrestrials. Some of the task force members, including parts of Afanasyev's staff, told a different story, insisting that Afanasyev was a glory hound and desperately wanted to have his name etched in history. Either way, the Americans and Germans decided not to push the issue, determining that the attempted extermination of subhuman intelligences was not worth pushing relations between the Soviets and the other superpowers to the brink.
To this day, Brabant V continues to be a radioactive wasteland. Although signs of resurrected osminogi civilization had arisen after the initial Soviet bombardment, the planet was yet again bombed (with various intensities) by the German colonization fleet sent there a few decades later, both the Soviets and Americans during the Collapse, once again during the post-Collapse communist revolutions, by the United Technocracies during their war with the Conseil, and finally by the Conseil themselves when they recolonized Brabant III and Brabant IV. Some osminogi still live on their charred homeworld, trying to get by however they could and suffering from an extreme fear of the “star gods,” but some were captured by pirates and slavers and bred offworld, and now many serve as pets or servants in the homes of Coalition CEOs and Conseil nobles. It is said that most osminogi view their masters similar to gods, as they tend to feed them and highly value them (albeit as expensive objects, not equal sapients).