Gwievft are large, aquatic eels that are typically found in underwater mycelium caverns, although they sometimes explore more open waters. Gwievft have an extremely venomous bite that can completely paralyze dolphins, sharks, and humans within hours and lead to death shortly after. During this time, the gwievft toxin has opium-like effects in the victim that work to keep it calm and avoid struggling. Gwievft toxins have been successfully extracted by natives for use in sacrificial and ceremonial drinks for centuries, although ranching them is an extremely dangerous job.