The Weather Wizard was already a violent criminal before he gained his powers. He had escaped prison and made it to his brother's house, where he discovered that his brother had created a bizarre wand that could control the weather. He wanted this wand so badly, he killed his brother to obtain it.
Weather Wizard first appears in the show Superman the Animated Series in the episode "Speed Demons" where it is revealed that he used to be an extortionist in Keystone City. While Superman and Flash help a race against each other he plotted to create a storm big enough to destroy the city along with the heroes. However with the help of his brother Ben, Flash and Superman are able to find and beat him.
He returns in the show Justice League in the episode "Hereafter" as a member of the Superman Revenge Squad. He helped them by creating storms for cover. Although they were able to teleport Superman away they all were beat and captured.
Later in the show Justice League Unlimited a wax statue of him appears in a Flash museum in the episode "Flash and Substance". Also in the episode he is shown in a bar where Flash villains hang out. He later joined the Legion of Doom and during the mutiny he sided against Lex Luthor and is killed when he is frozen by Killer Frost. In all three of these shows, he is voiced by Corey Burton.
In the show Batman the Brave and the Bold in the episode "Night of Huntress" he receives a tip from Calculator that Flash will be out if town and that he can commit crimes freely. In the episode "Requiem of the Scarlet Speedster" he appears helping his fellow Flash rouges. In the episode "Powerless" Captain Atom uses him as an example of villains that can easily beat Batman. He later returns in the episode "Triumvirate of Terror" as a member of the Legion of Doom. In this show he is voiced by Atkin Downes.
In the The Flash TV show of 2014, his brother Clyde Mardon is first seen in the pilot. He is first seen at a barn, shooting at policemen. He then boards a plane, which explodes due to the particle explosion. He is then seen robbing a bank with his new found power to create and control clouds. He is then seen driving a car, which Barry Allen catches up to with his superspeed. The car crashes and Clyde escapes by creating a giant cloud. He is finally seen cornered by Joe West and Eddie Thawne in the barn. He blasts then away, then creates a tornado headed for Central City. The Flash stops the tornado and Joe West shoots Clyde, killing him.
Mark Mardon finally appears in Out of Time. He attacks someone by shooting them with giant balls of hail. The person tells Mark that Joe West killed his brother. He is later seen when Barry is driving with Joe. Mark tries to kill them, but ends up only destroying the car. He is later seen at the police station trying to kill Joe, but The Flash runs in and grabs an item called the Wizard's Wand, which disables his power. Mark escapes. He is seen for the last time in Out of Time capturing Joe and destroying the city with a tsunami. However, this doesn't happen because The Flash messes with the timeline and imprisons Mark.
Powers and Abilities
As the name suggests, the Weather Wizard has the power to control the weather using his wand.