Third Assistant

From Tardis Wiki, the free Doctor Who reference

The Third Assistant was one of the Elders who assisted Senta in performing life force extraction on the Savages. He helped perform the process on Nanina. He went to help the Second Assistant when he caught Dodo Chaplet trespassing in the laboratory.

He tried to prepare her for extraction but Dodo broke free and held him in a stand-off by threatening to destroy the laboratory equipment. (TV: The Savages)