Highwayman

The Dark Rider was a painting of a highwayman at the International Gallery. It was animated by Mona Lisa and helped her capture Clyde Langer. While it guarded him, Clyde remarked the painting could not talk as it has no visible mouth, for which it was ready to shoot him. The others arrived before it did.

It was returned to its frame when The Abomination was destroyed, breaking the mental link that animated it.

_{Biography from the TARDIS Data Core article, licensed under CC-BY-SA}