The Krafayis were a species of space-faring omnivorous predators.
Biology
The Krafayis were large creatures with reptilian and bird-like traits. They had parrot-like beaks, quill-like horns, two wattles on the sides of their heads, long necks and quills down their tail.
The Krafayis were generally invisible, giving them the perfect defence. They could be seen by Vincent van Gogh, apparently due to his unique perception of the world, and in the reflection in a mirror on the species matcher. (TV: Vincent and the Doctor) They could also be seen in other reflections, such as in water. (PROSE: Blind Fury)
The Krafayis had yellow blood. (PROSE: Blind Fury)
Life cycle
The Krafayis were capable of travelling through the universe, moving from planet to planet to hunt. They preferred to travel to planets with oxygen/nitrogen atmospheres, such as Earth. They hunted in large packs with a strict hierarchy and had territories which spanned star systems. Eventually, they would depart the planet, leaving behind the weaker Krafayis. These Krafayis would be unable to rejoin the pack and in their loneliness would cause destruction and chaos until they were killed. (TV: Vincent and the Doctor)
History
The Krafayis were believed to be an ancient species from the Dark Times. Legends say that in the Old Times of Gallifrey, a Krafayis attacked the village of Slothe, killing many. A Gallifreyan, Presus, eventually confronted the Krafayis and after three days of fighting, the Krafayis was killed. (PROSE: Blind Fury)
In November 1890, a lone Krafayis was stranded in Auvers-sur-Oise, France because it was blind. It was responsible for many deaths in the area before it was stopped by the Eleventh Doctor, Amy Pond and Vincent van Gogh. The Krafayis was accidentally killed by van Gogh who expressed remorse at its death when he realised it was scared, not hostile. (TV: Vincent and the Doctor)
Alternate timeline
In an alternate timeline where the Eleventh Doctor never intervened, the Krafayis was painted into one of Vincent van Gogh's paintings. After the Doctor travelled back in time to investigate, the Krafayis was no longer depicted in the paintings. (TV: Vincent and the Doctor)
Other references
The Ninth Doctor once used the phrase "running around like a headless Krafayis." (AUDIO: The Bleeding Heart)
Romana once listed Krafayis as creatures she recognised from nursery rhymes on Gallifrey. (AUDIO: Babblesphere)