Fendahleen

Physical manifestations of the energy used by the Fendahl Core on Earth. The energy was initially focussed through the Fendahl Skull.

The Fedahleens were gastropodic creatures that fed off the dark emotions expressed at the moment of someone's death. The Fendahl, being a gestalt creature, needed to merge with twelve of these along with the Core. This would enable its complete transformation into a physical being, whereupon it could destroy all life on Earth.

The Doctor killed one Fendahleen with rock salt, and another was lost when its human host committed suicide. The other ten which surrounded the Fendahl Core at the moment the local time fissure implosion destroyed it, were simultaneously obliterated.