Fractal Guardian

Named for their behavior towards trespassers of ancient alien ruins on Europa, Fractal Guardians are a species of invertebrate lifeform.

Biology
Unlike most other lifeforms on Europa, but just like Humans, Fractal Guardians come in different variations of each other. As of now, two variants of Fractal Guardian are currently known to exist.

The first known form is a four-segmented, worm-like creature with spike-like limbs to propel itself through the water. Each segment of the creature has a small set of holes in close proximity to each other, though it is unknown what function these serve.

The second variant, considered more durable than its worm-like sibling, is a slower orb-like creature with only two sets of spiked limbs. Its round body is covered in a carapace for protection against both predatory creatures and invaders' weaponry.

Behavior
Unlike most creatures, they strictly target the main invaders themselves, but often don't bother with the vehicles arriving in, many explorers even stating that they ignore the submarines and only wait until after they venture into the ruins to attack. They are solitary, and often only one is found within a ruin, though multiple Fractal Guardians in one place have been reported in past expeditions.