The Fendahl: Proof that monsters on DOCTOR WHO don't have to be scaly, slimy, or composed of tentacles to be disturbing as hell.
It always comes back to Lovecraft.
In the present day of 1977, a group of evolutionary scientists run tests on a skull of a homo sapiens found during an archaeological dig in Kenya and determine it to be at least four-million years too old to exist. During one of the tests, the skull reacts and possesses the team's female member while also unleashing a swarm of deadly tentacled wigglies into the nearby area. Naturally such weirdness attracts the attention of the Fourth Doctor (Tom Baker), who arrives to investigate with his future-savage companion, Leela (Louise Jameson). What they discover is best summed up as "DOCTOR WHO collides head-on with H.P. Lovecraft," as a diabolical cult led by one of the scientists seeks to awaken and control the Fendahl, a gestalt entity of great malevolent power and intent straight out of the mythology of the Time Lords (the Doctor's race). The Fendahl devours life itself and in the past destroyed at least one entire planet and its population, and when it arrived on Earth all those millions of years ago and went dormant after being buried, its influence may have borne heavy influence upon the development of the human species. But whatever scientific and evolutionary revelations the Fendahl's skull could yield, the baleful entity must be utterly destroyed lest planet Earth be the next to meet its fate ate the hands of the life-eater.
The Doctor attempts to communicate with the Fendahl entity. It does not go well.
"Coming up next: Bugs Bunny and all your cartoon pals!"