|There is more information available on this subject at Sea Worm on the English Wikipedia.|
Sea worms are tiny, mundane creatures of Installation 04 that can be seen in the shallow waters of the Halo: Combat Evolved level The Silent Cartographer. They wriggle around near the surface of the water and do not interact with the player at all.
- These and the moths in the level 343 Guilty Spark are the only known indigenous creatures on Installation 04.
- The worms do not appear in Halo: Combat Evolved Anniversary's remastered graphics.