Blur

The Blur are a science-minded race of aliens who pursue knowledge for its own sake. They are named after the blur created by their environment suit's cloaking effect - these suits are humanoid, but contain an incredibly long and thin worm-like body. While the Blur as a whole are not malicious or militaristic, the experiments of one Blur faction led to the deaths of nearly every person on Earth.

Description
A Blur's true form resembles a white-colored ribbon worm or flatworm, only much longer. While never wider than a human finger, a Blur can reach several hundred feet in length, and the creature's total body mass is similar to that of a human. The nervous system and organs are distributed along the body's length, so a Blur has no single vital organ or weak point anywhere on its body. At each end, the body narrows to a nearly invisible point, which can be used like a syringe. A Blur can use these "syringes" to inject poisons or diseases, to take and test biological samples, and to initiate telepathic communication - some or all of these functions may be biotechnology rather than innate abilities.

Blur are surprisingly strong for such thin creatures and can assemble their coils into a vaguely humanoid shape. This shape has four legs and two arms, and the Blur's ends form two of its fingertips. Maintaining this walking form requires continuous effort, so the Blur use environment suits to make it easier.

The details of Blur diet, reproduction, and life cycle are unknown. It is suggested that they might reproduce by fission, but this is never confirmed.

Homeworld
The Blur hail from a mostly oceanic world with limited dry land. They evolved in that world's oceans and, for the most part, are still aquatic creatures - they find swimming much easier than walking and need their suits to move easily on land. The Blur's expansion beyond their homeworld was driven more by curiosity than actual need, so it is likely that their homeworld remains in good shape.

Culture & Society
Blur society is driven primarily by curiosity and scientific inquiry. They seek out knowledge for its own sake, with varying degrees of ethical restraint. They are not generally violent or militaristic, though they can cause terrible destruction if they deem it necessary.

The Blur are divided into two factions, the "pure" and "impure." The pure Blur carry out their studies and experiments with respect for the sanctity for life. The impure Blur are much more malevolent and dangerous, practicing science wholly without moral restraint and purely for the pleasure of discovery.

Technology
Blur technology far surpasses that of humanity, especially their biotechnology.

Environment Suits
Blur environment suits are vaguely humanoid in shape, with a tubular body, four legs, and two arms. The hands and feet each have three digits - the middle digit of each hand contains one end of the Blur inside the suit. The suit's head has two dark, oily eyeholes, though it is unclear if the Blur actually need these eyeholes to see. The suits have two layers. The outer layer bends light, making the suit almost completely invisible except for a blurring and rippling effect. The inner layer provides additional structure and protection. Often, those who see beyond the cloaking effect mistake the second layer for the actual creature. The suit can also repel physical contact to protect its wearer, but this ability needs to be recharged, and the suit is not otherwise very durable. Suited Blur generally use their sharp middle fingers as weapons, but also wield electricity-based ranged weapons that fire arcs of lightning.

The suits are not built, but are instead grown like fungi.

Biotechnology
The Blur are masters of biotechnology. The impure Blur can manipulate the human genome, adding a defect that spread to nearly the entire population. People with this defect can be manipulated further - the impure Blur can infect them with custom-made diseases or control their behavior with a single injection.

The Blur also developed a genetically targeted method of killing. The pure Blur used this to eliminate the impure-created defect from the human gene pool by killing all those infected. This effect could be targeted at a single person or spread across the entire planet at once. The killing effect instantly reduced the victim to white powder while leaving their surroundings unharmed. It is unknown exactly how this effect worked, but when activated it made a loud grinding sound.

Spacecraft
Blur spacecraft are made of metal and glow brightly when in use. The only ships seen are about thirty feet across and consist of two disks intersecting a sphere. The interior of the ship is a spherical space about eight feet wide, covered in wriggling organic tendrils that the Blur pilots presumably use as controls. Much larger spaceships must exist, since the Blur have abducted people, but these are never seen.

Other
The Blur claim to have the technology to see vaguely into the future and to influence (but not control) the behavior of other creatures without hijacking their genomes. The pure Blur used both technologies to influence surviving humans in order to save them from the impure Blur.