Scribe
From Tardis Wiki, the free Doctor Who reference
Scribe was one of the two social classes of Cerulian society, alongside the Masters. The Masters incorporated cerulium into bracelets and used them to control the Scribes, which they would use as slaves. Eventually a symbiotic relationship developed between the two; the Master was enchanted by the Scribes, who had no thought but to compliment and assist the Master. They were so amused with one another that they were oblivious to the threat of an incoming asteroid which destroyed their civilisation. (TV: Sirens of Ceres)