Mister Dread was a member of the Men in Black and the leader of three designated to guard the vault.
Dread was part of a mission of the Alliance of Shades to stop humans realising the truth about the Grey aliens. He tracked down the Tenth Doctor, Cassie and Jimmy, but was damaged by Night Eagle. He managed to rebuild himself and retrieve the ionic fusion bar, bringing it back to Dreamland, where he was apparently destroyed by the Doctor's sonic screwdriver. (TV: Dreamland)
In 1972 the Alliance of Shades was disbanded and the majority of his kind were decommissioned as a result. Despite this, the Alliance were unable to remove their hyperdimensional vault connected to St Jude's Hospital, where they stored their confiscated alien equipment. In light of this, Dread and two androids were re-assigned to guard the vault indefinitely. One of the activation disks for the vault was left in the care of Ocean Waters, while the other found its way off-planet.
In 2010, Dread and two other agents were located in St Jude's Hospital. When Androvax (in the body of a human teenage girl) entered the Hospital, Dread and the others were awoken by the perimeter alarms and chased him off. He and the other agents stopped Sarah Jane Smith after Androvax sent her and the others there to free his people. When he discovered that Sarah Jane had taken a clipping of Ocean Waters's abduction by aliens, he and the other agents attacked Ocean's house. Androvax managed to escape in Gita Chandra's body; Dread followed him, commandeering a van to the vault. He tried to use Gita and Rani Chandra as bait but was ambushed by Clyde and put back in his box, only to be activated soon after by Sarah Jane so he could use his power supply to transmat the Veil ship into space, saving Earth. Dread had used 450 years of power through that act, but since the vault had been sealed with Androvax's departure he had no further purpose and decided to deactivate himself. As suggested by Sarah Jane, he used some of his remaining power to wipe Gita's mind of her alien encounters before retiring. (TV: The Vault of Secrets)
Like most Men in Black, Dread's personality was cold and aloof. Dread claimed that the Alliance programmed him and the others without emotion because they believed they would make the androids less efficient in their duties, though this lack of emotion contributed to most of them being deactivated by the 1970s. Despite this, Dread displayed a certain level of pride in himself, claiming he was one of the Alliance's more successful and efficient models. Even though he claimed he had no sense of humour, Dread appeared to have developed a dry sense of humour. This was evident when Sarah Jane damaged his car and he was bothered by another driver. The driver said he should have found a new vehicle. Smirking, Dread told the man he would take the man's van and ripped the door off its hinges, frightening the man off.
Dread also displayed a level of ingenuity and cunning that seemed unique to him. Using his mindwiping abilities on Ocean, he also hid the second lock to the vault with her, convincing her that it was a piece of jewellery and conditioning her mind so she would not discard it. (TV: The Vault of Secrets)
He had the ability to remove his hand and produce a blaster, which shot green laser blasts. An organic being would be incinerated if the laser hit a living target.
Mister Dread had a Neuron-X Series 5 processor, a tritanic endoskeleton and a power cell that was capable of lasting for 500 years. Mister Dread was also able to mind wipe those who saw alien activity. This mind wipe, however, could also leave traces of Dread himself. As an android, he also had superhuman strength, capable of ripping off a lorry door with ease. (TV: The Vault of Secrets)
Although vulnerable to the Tenth Doctor's sonic screwdriver in 1958, (TV: Dreamland) by 2010 he was immune to the effects of Sarah Jane Smith's sonic lipstick while activated. The sonic lipstick was, however, capable of force-activating Mister Dread. (TV: The Vault of Secrets)
Behind the scenes
In Dreamland, Mr Dread was apparently destroyed, which possibly contradicts his later appearance in The Vault of Secrets. However, Peter Guinness supplied his voice for the character in the former, computer animated, story and Angus Wright played him in the later story, which would suggest that they were two different versions of Mister Dread.