Riffids

Riffids are a fictional species that appear in the science fiction novel "Project Hail Mary" by Andy Weir. In the narrative, they are a silicon-based lifeform encountered by the protagonist, Ryland Grace, on the planet Erid. Riffids are described as large, multi-limbed creatures with a crystalline exoskeleton that refracts light. They communicate through complex patterns of light emitted from specialized organs, a form of bioluminescence that also serves as a defensive mechanism.

The Riffids are a highly intelligent and technologically advanced species, though their technology is based on principles unfamiliar to humans. They possess a communal consciousness, meaning individuals are deeply interconnected and share thoughts and experiences. Their society is organized around a collective goal of survival and exploration of the cosmos. Riffids are known for their philosophical outlook and their deep respect for life, even forms of life vastly different from their own. They play a crucial role in the plot, providing essential assistance and knowledge to Ryland Grace in his mission to save Earth. Their biology, societal structure, and interaction with humans are key elements of the novel's scientific and thematic explorations.