Pilot Fish 1

A Roboform was one of a group of four who appeared on Earth disguised as Santa Claus. Appearing in advance of the Sycorax invasion of Earth, they were likened by the Tenth Doctor to pilot fish. (TV: The Christmas Invasion)

Behind the scenes
"When a band of Father Christmases attacked it was a sign that the bigger threat of the Sycorax was very near by."

- Pilot Fish 1's profile.

Three of the four Roboforms seen in The Christmas Invasion were each represented by an individual Battles in Time trading card.