A lonely research scientist, Doctor Simon Ecks discovered that the energy auras that surround every human being could be amplified, strengthened and given enormous powers and enabled to function separately from the host body.
Without waiting to test his invention, Ecks used it to create an energy duplicate of himself that he called Double X, and his fragile mind was unhinged by his energy duplicate, Ecks and Double X embarked upon a crime spree, using Double X's powers to overcome all opposition.
Eventually defeated by Batman and Robin, who destroyed Double X by destroying the machine that created him, Ecks was committed to Arkham Asylum. Months later Ecks escaped and using a previously hidden duplicate of his first machine, he recreated Double X only to be defeated by Batman again. With Ecks once more in custody and his duplicate machine destroyed, it appeared the threat he posed was over.
However, Double X was sleeping in Ecks' body, and years later when he realized this was the case, Ecks plugged his finger into an electrical socket, absorbing enough energy to free Double X once again. This time it took both Batman and Superman to overcome him. Double X later reappeared and teamed up with the Rainbow Raider, but the duo was defeated by Batman and the Flash.
Doctor Double X sat next to Beast Boy at a convention. Gar soon realized he was washed up and forgotten as a celebrity.
Powers and abilities
Doctor Double X is able to create an energy duplicate, known as Double X, an entity living in a symbiotic relationship with Ecks. Double X's energy-duplicate shares the consciousness of Simon Ecks, but can also act alone. The duplicate's powers of flight, energy blasts, and superhuman strength at a level that allows him to throw Batman into orbit. His powers are so strong that sometimes Batman had to seek help in defeating the villain. Double X requires regular infusions of electrical energy to sustain itself or it will lie dormant in Ecks' body.
In other media
Batman: The Brave and the Bold
Doctor Double X appears in the Batman: The Brave and the Bold episode "A Bat Divided" voiced by Ron Perlman. Doctor Double X tries to create a radioactive meltdown to increase his powers, but unknowingly creates Firestorm after he combines Ronnie Raymond and Jason Rusch. Unknown to everyone else, even him, he also split Batman into three parts. Doctor Double X later kidnaps Firestorm to absorb his radioactive energy, but the three Batmen rescue Firestorm and battle and defeat Double X. He later makes a cameo in "Joker: The Vile and the Villainous" where he was seen at the bar where the bad guys hang out.