Vermelith

Vermeliths are gigantic, lithotrophic silicon-based worms that inhabit interplanetary space. They are large enough to pose a major threat to starships, which they sometimes prey upon.

Anatomy & Physiology
Vermeliths are the size of large starships, averaging 1,200 feet (366 m) in length when sexually mature, and older specimens can grow many times larger than this. They resemble long, spiky worms with a hard, stony carapace. The spikes are larger at the front end of the body, ending in a toothy, lamprey-like mouths. The tail is long and whip-like, and ends in large spikes.

The nutritive dust released during reproduction supplies vermeliths with reflective properties, granting them immunity to radiation and electromagnetic pulses. They also have a number of internal organs allowing them to manipulate gravity, which protects them from gravity-based effects and allows them to project a blast of warped space; additionally, they use these organs to propel themselves through space.

Diet
Vermeliths feed on rock and metal. They generally feed on small bodies like asteroids and comets, but will also burrow into planetoid-sized objects, as they can tolerate low gravity fields despite their adaptation to deep space. Sometimes, they will attack and eat starships.

Reproduction and Life Cycle
Vermeliths are solitary hermaphrodites that rarely encounter each other. When they do, they both release clouds of gametes before attempting to drive each other off. The clouds congeal into dozens of egg-like cysts, which remain dormant for however long it takes them to encounter an edible object. Once a vermelith hatches, it can encyst itself again whenever it needs to. Vermeliths take centuries to grow to adulthood and live for thousands of years.