This article contains spoilers forDoctor WhoSeason 2 episodes “The Impossible Planet” and “The Satan Pit,” Season 4 episode “Planet of the Ood,” and Christmas special “The End of Time.”
Among the cast of alien species that populateDoctor Who, the Ood remain one of the most mysterious and — perhaps — among the most crucial. They don’t get much screen time compared to some otherDoctor Whoalien staples, but they play an integral role in several of the show’s weightiest plot lines.

The Ood are first introduced to viewers as a helpless, mindless race of cattle-like creatures who live only to serve their human masters. Over the course of the series, however, they gain incrementally greater levels of freedom and independence. Eventually, through their various encounters with the Doctor, they meet a fate that may surprise some audiences.
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Who Are The Ood In Doctor Who?
The Ood are an alienrace of friendly, sentient humanoidsthat appear in several episodes of the modern series ofDoctor Who. They have a distinctive appearance that might remind some horror fans of H. P. Lovecraft’s Cthulhu, and might remind some Dungeons and Dragons players of mind flayers. Like mind flayers, the Ood possess potent telepathic abilities that allow them to communicate as a hive mind and achieve feats of great psychic power.
Besides the tentacles that protrude from their faces where one might expect a mouth, the Ood sport another distinctive physical feature: a plastic orb attached to their heads by some kind of wire. The Ood are seen using this orb both as a means of communication and, in some cases, as a weapon capable of killing someone instantly upon contact with the cranium. While this apparently cybernetic attachment goes unexplained for a couple of seasons, it is eventually revealed that these balls have in fact replaced a portion of each Ood’s brain as a means of lobotomizing their entire species. This causes the altruistic Doctor to take drastic action on their behalf, contributing to one ofthe most impactful plot arcs of the series.

When Do The Ood First Appear In Doctor Who?
The Ood premier in Series 2 of the revival in the episode “The Impossible Planet,” which is the first of a two-episode plot line, the second being “The Satan Pit.” They do not appear at all in the originalDoctor Who, but they serve an invaluable function in the twenty-first century seasons. In “The Impossible Planet” and “The Satan Pit,” the Tenth Doctor (David Tennant) and Rose Tyler (Billie Piper) accidentally come across a small group of human researchers on a planet orbiting a black hole, assisted by their troop of loyal servants belonging to the “slave race” known as the Ood. According to the humans who own them, the Ood are perfectly happy to live a life of absolute servitude and do not wish for freedom.
At first, the Oodseem docile and harmless. They do as their human masters bid and stand motionless when they have no work assigned to them. However, a strange presence begins to manifest in this dark and impossible place, wielding the Ood as its weapon of choice. Their normally white eyes turn a luminous shade of red as something seemingly demonic hijacks their telepathic link and causes them to attack the base’s other inhabitants, including the Doctor and Rose.

Eventually, the Doctor discovers a Satan-like creature at the bottom of an enormous pit. He must flee the planet as it falls into the black hole, taking Rose and Ida (Claire Rushbrook), the last living researcher. The Ood are left on the station to die alongside the monster controlling them.
What Happens To The Ood in Doctor Who?
Luckily, the Ood who die on the impossible planet are not the last the Doctor encounters on his travels. In the Season 4 episode “Planet of the Ood,” the Tenth Doctor and Donna Noble (Catherine Tate) find themselves at the headquarters of Ood Operations, a massive company responsible for the sale and enslavement of countless Ood. Once again, the Ood are experiencing some kind of telepathic interference that causes their eyes to glow red and their temperament to turn violent. The Doctor and Donna discover that the CEO of Ood Operations, Mr. Halpen (Tim McInnerny), has kept the Ood brain — the center oftheir hive mind connection— captive while torturing it constantly. What’s more, they learn that Ood Operations lobotomizes the Ood they sell by removing their hindbrains, which they normally hold in their hands, and replacing them with translation spheres.
The episode ends with Mr. Halpen’s main servant, Sigma, revealing that he has slowly been turning him into an Ood by way of Mr. Halpen’s hair growth medicine. The Doctor frees the Ood brain, allowing the Ood to unite in their psychic song. This song extends across the known galaxy and causes all humans to release their enslaved Ood back to the Ood-Sphere, or the titular planet of the Ood, where the Doctor and Donna found and liberated the Ood brain.
TheDoctor WhoChristmas special, “The End of Time,” delivers the last part of the Ood’s broader narrative. Individual Ood do show up in other episodes and spin-offs, but such cameos lie outside the focus of this article. In “The End of Time,” Ood Sigma contacts the Tenth Doctor to inform him of the Master’s return. Since their liberation one hundred years ago, the Ood have become immensely powerful beings capable ofnavigating and manipulating time. Thus, they are able to warn the Doctor about the Master’s presence and help him transition into the Eleventh Doctor.
The Ood’s transformation from mindless drone to time-seeing eternals constitutes one of the most surprising sequences of the entire show. These creatures, initially used as a mere plot device in an episode with much larger cephalopods to fry, end up major players onthe board of time warfare. Not many beings inDoctor Who’s universe can boast the ability to see or travel through time. This places the Ood among the most powerful entities the Doctor ever encounters, and in any case, their story is certainly among the most inspiringDoctor Whohas to offer.