Crow
Crows were an Earth species of bird, described by the Fifth Doctor as "harbingers of doom". While crows were scavengers by nature, feeding on fresh meat such as roadkill killed by others, they did occasionally kill by themselves, although this usually only extended to field mice. (AUDIO: Plague of the Daleks, TV: The Day of the Clown)
The Twelfth Doctor claimed that crows were able to talk to humans, but they eventually ceased this as soon as they discovered humans were no longer capable of intelligent conversations. In the 2nd century, crows were capable of repeating phrases as well as a few words, such as "Doc-tor" or "Monst-er". When Kar sacrificed herself to be a keeper of the gate, her brother Ban told the crows her name. As a result, the cawing sounds that would become well known in the following centuries originated out of remembrance of Kar. (TV: The Eaters of Light)
In 1890, Vincent van Gogh painted crows soaring through the sky above a wheat field; this was one of his final paintings. (TV: Vincent and the Doctor)
A group of artificial Dalek-controlled crows mysteriously observed the Fifth Doctor and Nyssa when they arrived in 45th century Stockbridge. (AUDIO: Plague of the Daleks)
