The Meep were a peaceloving race until their planet was exposed to "black sun" radiation, transforming them into a ravenous horde of galactic conquerors who reveled in torture and depravity. Their battle fleets were finally defeated during a massive space battle, but the leader of the Meeps, the evil Beep, escaped. Crashing on Earth with Wrarth warriors close behind him, he faked benevolence and gained the trust of a couple of Earth children. However when the Doctor (in his fourth persona) stumbled into the situation, he soon realised the truth, and helped bring the war criminal to justice.
Fifteen years later he was given parole, and he returned to Earth, seeking revenge. Again his plots were thwarted by the fourth incarnation of the Doctor, who somehow trapped him inside a children's movie, For the Love of Lassie.
The Meep escaped and attempted to take revenge on Earth for the indignities it had heaped on him by using televised signals to take over the planet. This time he was thwarted by the sixth incarnation of the Time Lord.
Much later he attended Bonjaxx's birthday party at Maruthea, although he may not have been an invited guest. Blitzed out his skull, he made a very poor attempt to kill the seventh and nth Doctors, and accidentally precipitated a bar room brawl instead.
Beep was last seen having gone back in time to 1979, where he attempted to broadcast black sun radiation through people's televisions, thus transforming Earth into a psychotic world like his own. But at the television centre he planned to use he mistook an actor called Tom Baker for his hated foe, and while distracted, the eighth incarnation of the Doctor stopped his plot.