Malus

The Malus was a creature re-engineered by the Hakolians for their invasions.

It was sent to Earth in the 17th century, where it laid in suspended animation. In 1643 it was awoken by the battle at Little Hodcombe and began feeding on the psychic energy generated by the negative emotions. The Malus went dormant again once the violence subsided.

In 1984, the Malus was discovered by Andrew Verney and Sir George Hutchinson. The creature took control of Hutchinson and tried to use him to generate more psychic energy upon which to feed.

The Malus was defeated when the Doctor used his TARDIS to block its feeding, and when Hutchinson was killed, it destroyed itself and the church it had based itself in. (DW: The Awakening)

Despite its being a villian the Doctor showed great pity for the Malus, claiming that killing was the only thing it knew how to do. He suggested it was a benevolent creature the Hakolians had re-engineered into a killing machine.