Vicky's Reign of Terror refers to the dictatorship of an alternate reality where, after Vicky the Evil Babysitter get fired for erasing a videotape that the Turner family were saving so that they could use it to get their own reality show, she decided to take over Dimmsdale and wage war on Earth. Timmy Turner must now stop her and never return her to babysitting at all costs for life! Unfortunately, every time Timmy wished she was not the supreme ruler of something, she became a supreme ruler of a very most powerful position.
Timmy's parents planned on attending a cinema, leaving Timmy once again, alone with Vicky. But this, time Timmy planned on exposing Vicky as the mean babysitter that she was. He had his fairies poof his parents back to the living room where they viewed videos of Vicky torturing Timmy in a dungeon or swirly. However, the Turners were too oblivious to the obvious evidence. Luckily, Timmy had anticipated this and made sure that Vicky taped over his parents home movie video, which Mrs Turner briefly instructed Timmy not to mess with, and was playing right in front of them. The Turners finally realized the truth at last, just Vicky came in with two electrical saws. At Timmy's request, they fired Vicky, then decided that Timmy was old enough to take care of himself.
Determined to get a job, Vicky went all over Dimmsdale, but the best she could do in each job was torture people, resulting in her getting shunned by all her bosses, both literally and figuratively. Eventually, she went to the mayor and revealed to Chompy the Goat that the mayor indulged himself in eating goat meat, causing the goat to chase him out of his office. Vicky then named herself the new mayor and took over Dimmsdale, with the help of her newly established ape army, renaming it Vickyland. Timmy, who was enjoying the time of his life with his godfamily, staying at home while his butler Jensen did his grades at school, soon discovered that getting Vicky out of his life caused her to ruin everyone else's. Wanda proposed that they took fire-breathing battle-rhinos and a lion-cloth warrior to Vicky to depose her; however, they lost badly, and Timmy tried wishing that Vicky wasn't the mayor. Unfortunately, Vicky somehow became President of the U.S.A. Timmy tried unwishing again, only for Vicky to become a supreme galactic warlord and began attacking Earth with her Star-Destroyer-like warship. To save the Earth, Timmy reluctantly wished that Vicky was his babysitter again in order to maintain peace. Then, Mr. Turner and Mrs. Turner lost the Reality Contest and entered the Dancing with the Cars contest, only to instantly get hit by a car and subsequently taken to the hospital. At night, Timmy and Jensen were tied by a rope on a train track when a train with Vicky on board tried to run them over. Jensen asked Timmy that Jensen liked to have a raise and Timmy said that Jensen would get it. In the end, The Mayor of Dimmsdale was still running from Chompy. The Mayor said that he loves Chompy.