Dorium Maldovar

Dorium Maldovar was a black marketeer in the 52nd century who owned a bar that gained its wares through questionable means. He was beheaded by the Headless Monks but his severed head, which retained its life and sentience, was kept in the Seventh Transept.

Dealings
In 5145, after hearing she was looking for time travel technology, Dorium met with River Song in the Maldovarium bar to offer her a vortex manipulator "fresh off the wrist of a handsome Time Agent" and wonder if she had a "pretty toy" as payment for him. River offered him a Callisto Pulse which could disarm the micro-explosives she had put in his wine. (TV: The Pandorica Opens)

Dorium sold a Judoon's brain that contained a security protocol to a trio of Headless Monks. They paid him with a bag of sentient money. As his customers left, he questioned their motives for kidnapping "the child" and told them not to provoke the Eleventh Doctor's anger and rage. (WC: Prequel (A Good Man Goes to War))

Demons Run
One day, Dorium Maldovar was fearfully closing down his bar in a hurry. He was caught by Colonel Manton and Madame Kovarian, who asked him what he knew; a month they had been on Yellow Alert after Amy's baby was born and the Doctor hadn't done anything. Dorium explained that there were numerous people throughout time and space who owed the Doctor a debt for helping them; the Doctor was gathering an army. Dorium explained the stories about the Doctor were true and not myths. Seeing they were getting nowhere, Kovarian and Manton left. Dorium prepared to follow suit, but found the TARDIS had landed in the backroom of his bar. (TV: A Good Man Goes to War)

Dorium was one of many people who owed the Doctor a debt. So he was summoned to help rescue Amy and her baby at Demon's Run. He did not serve in a combat role, but hacked into the station's computer and discovered that Melody Pond had "human plus Time Lord" DNA.

Dorium made a fatal mistake when he and the others were surrounded by the Headless Monks. He believed they were his friends and would not hurt him. He approached them with open arms, but they swiftly decapitated him and added him to their ranks. His headless body was subsequently killed by the Doctor's remaining allies in their fight against the monks. (TV: A Good Man Goes to War)

Post-beheading
The Doctor was told by the alien Gantok that Dorium had information about the Silence. They went to the Seventh Transept, where the heads of those whom the monks had beheaded were stored. Dorium's head was in a box, alive and able to speak. He told the Doctor that on the fields of Trenzalore, at the fall of the Eleventh, a question would be asked, a question that must never be answered. The Doctor took him aboard the TARDIS. Dorium tried to explain to the Doctor that he must die at some point.

Later, a Headless Monk was seen carrying Dorium's head to the Seventh Transept. Dorium realised it was the Doctor, but wondered how he could still be alive after the Lake Silencio incident. The Doctor had used the Teselecta to fake his death. As the Doctor left, Dorium warned him Trenzalore and the Fall of the Eleventh still awaited him. Dorium called after the Doctor the first question in the universe, which he had been running from his entire life: "Doctor Who?" (TV: The Wedding of River Song)

Iris Wildthyme and Panda once encountered Dorium, who told Iris that soon she would face "the Penultimate Question". (PROSE: From Wildthyme with Love)

At some point, the Eleventh Doctor dropped by the Maldovar Market and picked up Handles. (TV: The Time of the Doctor)

The Twelfth Doctor occasionally used Maldovar as a bowling ball. On one occasion, the Doctor brought Maldovar to a game with Strax. However, Strax destroyed the targets before the Doctor could get his turn and Maldovar didn't get used. (COMIC: The Adventures of Strax & the Time Shark)

Personality
Dorium Maldovar was a friend of the Doctor's despite his dealings with criminals and even the Doctor's enemies. He respected the Time Lord, to the point of almost being afraid of him which was shown when he warned Madame Kovarian that it was not a good idea to make the Doctor angry. Dorium had a tendency to complain, especially shown after he was beheaded. Although he was an associate of Kovarian, the Silence and the Headless Monks, Dorium's loyalty was to the Doctor. He helped the Time Lord rescue Amy Pond, getting himself beheaded in the process. He didn't seem too bothered by his beheading, joking with the Doctor about it and commenting that living without a body actually wasn't so bad. He could keep himself entertained with a chip he had installed in his skull, as he said that the wifi in the Seventh Transept was excellent. (TV: A Good Man Goes to War, The Wedding of River Song)

Behind the scenes

 * In a parodic Doctor Who Adventures comic series called Alien Babies!, Dorium is also in charge of a baby daycare in the Medusa Cascade.