Warning: Some of the abilities and actions this monster does are akin to a Basilisk and not a Gorgon, but it's easier to go with Gorgon and Gorgonites than it is Basilisk and... however you word the sub-plural of that.
Gorgon - A flock of ~hundreds of smaller, black-skinned creatures possibly titled "Gorgonites" that are incredibly fast and agile. Think Sardines or Starlings except angrier, more compacted, and more agile. They interconnect to each other to form a sort of super-highway intellect. All brought together to create one form, but still all separate.
Description of Gorgonite: Small, diamond-shaped. 6 short, strong legs with sharp "claws" on the end used to help it clinch into things to keep itself stable. 4 sleek, sharp eyes with a dark blue/black hue to them. Body is jet black. Entirety of its back is dedicated to 2 wings that "flap" incredibly fast. Very agile. No mouth. Possibly incredibly small antennae on head. Overall very sleek, slim design. Should look like it could cut flesh with its carapace. Space around the creature has a slight, clear "warp" effect to represent the intense energies emanating from it (which is its way of communicating to its swarm/keep closely connected to them in flight). The last effect is entirely optional to the design.
When these creatures form the Gorgon, they gain powerful abilities:
Paralysis - The swarm furls around itself a few times and suddenly disperses in clusters to a wide area (roughly a 20 meter area, would need testing to perfect). Between the clusters of Gorgonites spawns a strange energy - possibly the very energy they use to keep themselves to tightly packed together - that appears in what seems like the shape of snakes. This energy causes all wildlife/hunters caught within it the lose their mobility for a few seconds (maybe upwards of 5 or 6 seconds paralysis with a very long cooldown).
Stare - Gorgon locks onto a target and forms what looks to be a head with harsh eyes. These "eyes" project a strange energy at the target. As long as this stare is not interrupted, the target will rapidly lose health (even through shields!) after it has been locked on for a few seconds (possibly 3 second lock-on with a moderate cooldown). This gains Gorgon and minuscule amount of health back if it has any missing. If anything hurts Gorgon, the ability is automatically deactivated and put into cooldown. This combos with Paralysis, but by the time Stare would start to drain life the hunters would be free from Paralysis and have a chance to at least prevent some of the damage. Long cooldowns can prevent these two abilities from being abused constantly.
Whirlwind - Gorgon takes a tornado-like form, swirling quickly as its Gorgonites act like razor blades. Moves across the ground somewhat slowly, but causes decent damage if a hunter or animal is caught in it and stays in it for long. Is tall enough to catch jetpacking Hunters.
Sleeper - Aim at a target and "fire". A single Gorgonite is burrowed into a Hunter or wildlife, causing incredibly small amounts of damage over time (possibly 20 or so seconds). This highlights the target and slows it down until it wears off.
The normal melee attack of this monster would be a length of Gorgonites rapidly protruding from the main swarm and "stabbing" whatever it attacks, like a spike out of a blob.
The Gorgon floats, but leaves behind streaks of the Gorgonites energy on the ground behind it when careless (i.e. not sneaking).
Upon feeding, the Gorgonites furiously buzz around its food and drain it similar to Wraith. Could also have them cut through the actual carcass.
Upon "boosting" forward to gain ground (like Goliaths jump), the swarm dissipates outward as it boosts forward and then comes back together.
Upon sneaking, the Gorgonites don't buzz around wildly like normal. Smaller form, much more concentrated. Less noise, lower to the ground. etc
Origin: A small, parasitic insectoid was found on Shear. It produced interesting energies, which upon research proved to be useful in stopping blood flow and removing blood similar to a leech on Earth. The quizzical part was that it had no mouth. But so long as it was close to a living being, after a few moments of staring, it could siphon blood. It seemed magical, and all the testing and research on Shear couldn't figure out how it did what it did. Yet the potential medical advancements were there, and testing continued on this lone creature. Until it wasn't alone.
Personnel around the facility started reporting sightings of the insectoid all over. On ceilings, in trashcans, outside on the ground, etc. Every time it would be spotted, it would quickly skitter away. Some complaints were made about a sickness spreading around, blaming the recent paranoia about project SIphon (they weren't very imaginative with their names) and the recent sightings. Tensions became high as both sightings and sickness became worse. A few left the facility, and those were the only lucky few.
Amidst a particularly dark night on Shear, a great humming sound could be heard outside the facility. The few guards they had became aware of this noise and went out to investigate. One desperate gunshot rang out amongst the hellish buzzing, and that was the only challenge that night to the noise that rendered Zulta Research Facility dead and full of bones. A single distress call was sent out with no message attached.
A team of Hunters were sent in for recovery of this interesting specimen, codenamed "Siphon", since there were reports of a quick, massive beast in the area. Some of the bodies found were still perfectly intact, but looked to be frozen in place and empty of all blood. A strange predicament, as nothing they had encountered yet was capable of this. Was this mass murder? Was there technology that did this sort of thing? Is that was Siphon was, a device to siphon blood?
Having nothing to go on, the team leaves Zulta and moves to search the surrounding area for anything. A slight buzzing noise in the distance catches the ear of expert trapper Abe. Slowly, he approaches a thicket and peers through some leaves to see a swarm of small, black insects. Puzzled, he watches as it angrily buzzes around a small creature. Over a few seconds, the creature stops all movement and falls over onto its side perfectly still like a stone.
"Holy shit," Abe says, a bit too loudly. The swarm hears him and turns towards him.
"it's like a motherfucking Gorgon!"
This is a lot at once, with probably a bit too much effort in it. But I love the idea of a swarm-like creature that, when the smaller creatures come together they can do incredible things.