Jesus3747
The creatures are carbon-based hairless humanoids with tan skin. They have long arms, long fingers, and their eyes are on the ends of tentacles protruding from their heads, similar to a snail. Their bone structure is fairly standard for a humanoid race, though it seems some of them were augmented with metal, likely bone reinforcements. The metal is made of a compound that you have never seen before.
If the creatures did indeed commit suicide together, it was extremely well coordinated, all of the deaths happened in less than a millisecond, and the means by which they did so is unclear.