Clynex

Clynex was of a creature of and unknown entity. When Animus arrived on Voris, he drained Clynex's energy. Some years later after the Doctor the defeat of Animus, Clynex revived and started killing and draining the energy out of all Menoptra around him. By exciting Clynex's fundamental resonant frequency with his sonic screwdriver, the Doctor was able to destroy Clynex. (DWA: The Naked Flame)