A slug-like creature that Hoshi Sato brings back from an alien planet and frets over, mirroring her own difficulty in adapting to life aboard a starship.
Sluggo appears in Fight or Flight. Hoshi collected the animal on an away mission, and at the start of the episode it is sitting listlessly in a container in sickbay, refusing whatever she and Phlox offer it.
Phlox remarks that it might make a meal for one of his other creatures, which does nothing to calm her. The slug's failure to thrive in an unfamiliar environment runs in parallel with Hoshi's doubts about whether she belongs on Enterprise at all.
By the end of the story she has faced a hostile alien ship and found her confidence as a translator. She and Phlox take Sluggo down to a planet with conditions suited to it and let it go.