The Marcyam is a fierce aquatic serpentine beast from the planet Syrte. It has red blood and its skin is considered highly valuable. They rise from their burrows after storms and it is believed the plant spores in the air irritate them, contributing to their aggressive behavior.
- Valérian and Laureline:
- Empire of a Thousand Planets (1971)
- The Time Opener (2010)
- The Inhabitants of the Sky: The Cosmic Atlas of Valérian and Laureline (1991)