Nothing is known about Gizmo's early life outside of him being badly bullied as a child for his interest in science and engineering, which would give him a chip on his shoulder for the rest of his life. A clear genius, he established himself at a young age as an inventor, able to create complex inventions and deadly weapons from the most innocuous household objects, such as hairdryers, spoons, and even a vacuum cleaner. He sold these gadgets to criminals and civilians through his company, Gizmo Inc. Eventually he became actively involved in villainy when he decided to expand his business by joining the Fearsome Five.
Gizmo was created by Marv Wolfman and George Pérez. He made his first appearance in The New Teen Titans #3.
The New 52 reboot appears to have erased Gizmo's death and subsequent resurrection, as he does not exhibit any decomposition.
Major Story Arcs
Gizmo clashes several times with the Teen Titans, as part of the Fearsome Five or as an independent villain. He briefly reforms and joins STAR Labs, but is attacked and shrunk to microscopic size by vengeful former teammate Psimon. He remains trapped in this state for several years before somehow returning to his normal size, upon which he reverts to villainy, teaming up with Mammoth.
Five by Five
Gizmo is drawn into a plot by Doctor Sivana and other former allies to short sell LexCorp stock by stealing account information and killing people who happen to be in LexCorp buildings, with Gizmo blowing up a radio station and disabling it. He and the team escape a confrontation with the Outsiders, and he is amongst those who attempt to sway Sivana to attack a LexCorp nuclear missile facility. Sivana refuses, and fatally shoots Gizmo in the head in order to dissuade the rest of the team from taking the facility against his orders.
Gizmo is resurrected some time later by Macintech Research & Development sometime afterwards to produce technology for them and to reverse engineer criminal equipment for their own purposes. Though he is partially decomposed, he immediately deposes the company's CEO and gains entrance to the team of technology-based super villains known as the Silicon Syndicate.
Gizmo is invited to join the Crime Syndicate's Secret Society of Super Villains. He does so, and he and other members of the Fearsome Five are sent after the Rogues. He is trapped in a mirror alongside several other villains and shattered.
Teen Titans Go!
The version of the character designed for the Teen Titans animated series has appeared several times in the comic book adaptation of the show.
Powers and Abilities
Gizmo possesses a genius-level intellect, focused particularly around the invention of technology and the modification of existing items to create useful tools or weapons. He has no fighting skill beyond that granted by his technology, through he is a decent marksman with his weapons.
A prepubescent Gizmo appears as a minor villain in eleven episodes in this series. He is notable as the only villain to physically appear in all five seasons. He is typically seen in association with the HIVE Five, but occasionally appears as a villain in his own right. He probably became the leader of the HIVE Five after Jinx left the team. His first appearance is in "Final Exam." He is voiced by Lauren Tom for most of his appearances, and by Tara Strong for his appearance in "Titans Together."
Teen Titans Go!
Gizmo appears as an antagonist in several episodes in this series, occasionally in association with other villains and occasionally on his own. He is explicitly identified as the leader of the HIVE Five in this incarnation. His first appearance is in "Laundry Day." Lauren Tom reprises the role.
Gizmo appears as a boss in both the console and Game Boy Advance games under this name. Lauren Tom reprises the role.
DC Universe Online
Gizmo appears as part of the downloadable "Sons of Trigon" content. He is voiced by Michael Wollner.