Graham Sleight commented that the voiceless Yeti robots, and similar monsters such as the Autons and the maggots in "The Green Death", are controlled by another entity and are merely there to provide a threat, leading to the Yeti and similar monsters being less interesting than monsters that could talk or reason with the characters. In contrast, Fraser McAlpine and Nick Page felt that the Yeti being controlled gave them greater menace. McAlpine says this gives the Yeti menace because, being controlled, they can't hold any feelings or grudges of their own and act only as the fierce physical agents for whoever can control them. Page reflected that 'the Great Intelligence... always turned off their power when it was not required', creating suspense when characters interacted with a seemingly dormant Yeti.