Snell is a suspicious villager on Dilmer III who tries to expose Mariner, Tendi and T'Lyn as witches during their year undercover.
Snell is a native of Dilmer III, a pre-industrial world where time passes far faster than aboard the Cerritos. In Fully Dilated, Mariner, Tendi and T'Lyn spend a year undercover on the planet while the ship's transporter is repaired.
Tendi's scientific efforts, including reactivating the head of an alternate-universe Data, and T'Lyn's agricultural innovations draw Snell's attention. He tries to expose the three women as witches, but they manage to discredit him in front of his community.