Nitrium Parasite

Nitrium Parasites are a non-solid species of metal parasite which naturally inhabit the Pelloris field, an asteroid belt rich in nitrium, but can infect starships as well. This creature obtains energy by metabolizing nitrium, a metallic alloy which naturally occurs in asteroids and is widely used in Federation starships.

The Nitrium Parasite was first encountered by the USS Enterprise-D in 2368. It was living inside an asteroid of densely packed nitrium and chrondite, which had left the Pelloris field and was heading for impact on the inhabited planet of Tessen III. When its asteroid was destroyed by the Enterprise, the parasite moved to the ship itself and started feeding on the nitrium, damaging several of the ship's systems. Its presence was detected on time and a nitrium-rich particle beam was used to drive the parasite back to the asteroid belt.