Large invertebrate aliens with an unreadable language, one of which attaches itself to B'Elanna Torres and links its organs to hers in the Voyager episode Nothing Human.
The cytoplasmic lifeform appears in the Voyager episode Nothing Human. In 2375 Voyager traces a burst of energy to a damaged ship and beams aboard its only occupant, an injured creature resembling a huge insect or crustacean, whose speech the universal translator cannot handle.
In sickbay the alien leaps onto B'Elanna Torres, pierces her body and begins using her organs to keep itself alive. The Doctor, with no knowledge of such anatomy, creates a holographic consultant based on the Cardassian exobiologist Crell Moset.
The pair devise a way to separate patient and parasite without killing either, while the crew learns that the real Moset gained his knowledge through experiments on Bajoran prisoners. Others of the alien's species arrive and take the survivor home. The Doctor later deletes the Moset programme and its research.