Megavolt (real name Elmo Sputterspark) is a recurring antagonist of the Darkwing Duck franchise. He is an insane anthropomorphic rat with the ability to control electricity and a former classmate of Darkwing Duck's in high school, where he gained his powers after bullies sabotaged his science experiment. He's also a member of Negaduck's Fearsome Five.
As revealed in the episode "Clash Reunion", as a teenager, Elmo Sputterspark was fascinated with electricity and magnetism and, along with Drake Mallard, was tormented by Hamm String, the local school bully, because of his "nerd" status. During a static-electricity experiment gone awry because of a couple of school jocks, Elmo's body became infused with so much electricity that he was able to harness its power and shoot it at any target he chose. The brightness of the electricity caused his eyes to shrink (explaining the goggles). The trauma also affected him psychologically, causing him to go completely insane. It is said that he disappeared from school sometime before graduation and began his villainous career just after that.
At the high school dance, he showed up in a yellow suit and tried to give himself the name "Megawatt", but the band that was playing at the dance had the same name, so to avoid ambiguity, he gave himself the name "Megavolt." However, Drake Mallard had defeated him as his new identity, "Darkwing Duck". Neither would see each other until many years later, and again on opposing sides.
Over the years, Megavolt became one of Darkwing's most formidable enemies, and would often be seen partnered up with Quackerjack. Both of them would also become part of Negaduck's group, the Fearsome Five.
In "Beware the B.U.D.D.Y. System!", Megavolt - or rather, an actor playing him - makes a cameo appearance on the Darkwing Duck TV show when Launchpad is explaining to Dewey about Darkwing and the actor who played him, Jim Starling.
In "The Duck Knight Returns!", Dewey, who was put in charge of production of a Darkwing Duck movie by Scrooge (to director Alistair Boorswan's dismay), had the idea of casting an actor to play Megavolt in the final scene of the movie. When Scrooge looked the actor hired by his grandnephew over, he stated that "the villain's mustache [had] to be at least twice as twirly". However, no one except an oblivious Launchpad knew that the Darkwing at the movie set was not the actor hired to play the character, but Jim Starling, who attacked the Megavolt actor and commandeered the lightning ray gun as the studio was set ablaze. The Megavolt actor was last seen evacuating the studio with the other actors as Jim insanely declared that he would film the finale and kill anyone who got in his way.
In "Let's Get Dangerous!", the real Megavolt is summoned from an alternate dimension where the events of the Darkwing Duck TV show actually happened by Taurus Bulba, to assist him in his scheme alongside Quackerjack, Bushroot and Liquidator.
True to his name, Megavolt has the ability to manipulate electricity. In battle, Megavolt tends to shoot lightning bolts and electrocute his enemies as well as to defend himself. Since his suit is designed to absorb electricity, defeating Megavolt with his own powers ultimately makes the villain stronger. In addition to summoning lightning, he can activate and control nearby machines to do his bidding.
Megavolt's greatest weakness is that he shorts out completely whenever he comes in contact with water. Because of this, Darkwing has defeated him numerous times when engaging him in battle.
In issue #6 of Dynamite Entertainment's Darkwing Duck comic book, it is stated that Megavolt was apparently responsible for Dr. NoGood's inexplicable resurrection; how exactly he did it is never elaborated on, though, as he was never shown to have the ability to bring dead characters back to life in the cartoon or the previous comics. This is one of many reasons the Dynamite comic is not considered canon to the cartoon.
Megavolt is similar to the Spider-Man villain Electro and the Superman villain Livewire, as the three of them have the powers of electricity and are vulnerable to water.
Being voiced by Dan Castellaneta, who is best known for voicing Homer Simpson and other characters on The Simpsons, Megavolt's voice resembles that of one of Castellaneta's Simpsons characters, Krusty the Clown.
Darkwing has some respect for him and has referred to him as his arch-enemy, a title Megavolt thinks of as an honor.
An aside comment from Darkwing in his premiere episodes revealed that he sent Megavolt to the electric chair "twice." This indicates that Megavolt has committed crimes of a capital nature.