A Crustacean was a class of animal life with hard heavy shells. One known crustacean creature was The Sleeper, which dwelled on the planet Dathomir. During the Clone Wars, Quinlan Vos killed the Sleeper while under the tutelage of former Sith assassin Asajj Ventress.
- Dark Disciple (First appearance)
- Last Shot
- "The Wine in Dreams"—Canto Bight (Mentioned only)
- Star Wars: The Last Jedi: Expanded Edition (Mentioned only)
- "Vengeful Waves"—Star Wars: Myths & Fables (Mentioned only) (Appears in flashback(s))
- "Tales from Wild Space: The Best Pet"—Star Wars Adventures 5 (Mentioned only)
- Star Wars: The Last Jedi: Incredible Cross-Sections (Appears in hologram)