H is for... Halpen

Klineman Halpen was the CEO of Ood Operations, which marketed and sold Ood as servants across three galaxies in the 42nd Century. His family had owned the company for generations. He visited the Ood-Sphere in 4126 after one of his executives had died in mysterious circumstances, and to personally investigate the outbreak of an illness termed "Red Eye" which was causing the Ood to become aggressive. He was accompanied at all times by his own personal Ood servant - Ood Sigma. He was becoming obsessed with losing his hair, which he put down to stress, and Ood Sigma would be called upon to administer a hair tonic at regular intervals. Halpen considered the Ood as little more than animals, and was quite prepared to wipe out thousands of them if it would stop the "Red Eye" contagion from spreading. His father had shown him the gigantic Ood brain when he was a child. It had been found many years before and was surrounded by a dampening field to cut it off telepathically from the Ood. He was concerned that the field was weakening and causing the contagion. On learning that one of his scientists - Dr Ryder - was really a member of an Ood liberation organisation, Halpen killed him by throwing him off a gantry, to be suffocated by the brain. However, Ryder had reduced the dampening field, causing an Ood revolt. Halpen planted explosives to destroy the brain, and was on the point of killing the Doctor and Donna Noble, when he began to feel unwell. Ood Sigma revealed that he had been giving his master Ood graft in the hair tonic. Halpen was converted into an Ood himself. Ood Sigma informed the Doctor that he would look after him.

Played by: Tim McInnerny. Appearances: Planet of the Ood (2008).

• McInnerny first came to fame playing the dim-witted Percy in the first series of Blackadder. He returned as another Percy in the second series, and then again as Captain Darling in the fourth. He also made a guest appearance in an episode of the third series.
• He was initially reluctant to appear in guest roles in established series, but made an exception for Doctor Who. He has since relaxed his rule and appeared in many TV series - including Sherlock and Game of Thrones.