Smiler

The Smilers are androids used aboard Starship UK.

Description
The Smilers are human-like androids, mounted in booths located around the Starship UK. Their main goal was to serve as a security system for the spacecraft, but they also served other purposes, such as information consultants and automatic teachers who enforced strict grading systems for pupils. If any adult broke the law or was declared unncessary, the Smilers would have them fed to the Star Whale, while the children were forced to work in the Tower of London. The Smilers could rotate their heads to show three faces: happy, displeased (as a warning), and angry (when attacking).

Smilers would normally display a calm, happy face if citizens obeyed the rules. However, since their smiles were more often than not unsettling, as Smilers could switch their faces to frowning expressions if they caught the sight of anyone disobeying the rules of Starship UK. This served as the one and only warning that they gave to a person to cease their actions immediately. If this warning was ignored, the Smilers would change their faces to an enraged face with growling teeth and red eyes, and then engage in a brutal punishment. While the Smilers appeared to be just heads, in extreme circumstances, their entire bodies would leave their booths to attack. The Smilers' presence terrified the population of Starship UK, making them unable to go near the booths. This meant that the area around the Smilers was completely clean, as stated by the 11th Doctor. The Smilers can also recover from damage, such as bullet shots, through the usage of built-in repair capabilities.

Appearances
Doctor Who Series 5 - The Beast Below (2010)