The Mentor (Death to the Doctor!)

The Mentor was a rather pathetic, overweight villain imitative of of the Master most frequently encountered by UNIT. Like the Master, he had (or thought he had) hypnosis-based mind control powers.

Biography
When confronted by the Third Doctor, who remained unimpressed, and the Brigadier, the latter pulled a gun on him.

Later, he appeared at Research Base Truro, where he met with several other minor adversaries of the Doctor in his various incarnations, who turned on each other as a result of their mutual suspicion. The Mentor died in a three-way shoot-out with Bolog and Plink, two of the Doctor's other very minor enemies.

As with the others, when the Tenth Doctor arrived in Truro in the the TARDIS, he did not recognise the body. (COMIC: Death to the Doctor!)