Jamie (The Empty Child)

Jamie was a young boy who had been wearing his gas mask during an air raid in the London Blitz.

Jamie was killed and had a massive head trauma on the left side, partial collapse of his chest cavity on the right and a gash on the back of his right hand. He was reanimated by the Chula nanogenes that had leaked out of a crashed medical transport ship. His only thought was to be reunited with his mother, and he wandered the streets of London, a gas mask forever merged to his face, asking everyone, "Are you my mummy?" Because the nanogenes were unaware of what a human looked like, they began transforming all humans with whom they came into contact into gas mask zombies.

In the end the nanogenes were able to use DNA from both Jamie and his mother, Nancy, and restored him to normal. (TV: The Doctor Dances)

More than 60 years later, the Tenth Doctor jokingly quoted Jamie's repeated question, "Are you my mummy?" when forced to don a gas mask during a Sontaran attack. (TV: The Poison Sky)