Because of the judgment he received based off of his looks, Killer Moth decided to become a super villain.
Reuniting with Silkie
Killer Moth created Silkie to be a harbinger of doom, but the maggot separated from the villain and was adopted by Starfire through unknown means. Afterwards, Killer Moth traveled around the area and placed Missing Silkie posters with a reward in the hopes of being reunited with him. One day, when he attempted to take over the world by his minions, each one was destroyed by the T-Plane, which was piloted by Robin, Beast Boy, and Cyborg. He cursed the Titans for foiling his plot, but they instead handed him Silkie, delighting the villain. He thanked the Titans for returning Silkie, but they refused to leave until Killer Moth rewarded them. Later, Starfire and Raven visited Killer Moth's hideout to check on Silkie as Starfire was certain that he wouldn't treat Silkie with love. When proven wrong, the girls prepared to head back to Titans Tower, but overheard Killer Moth announcing his plan to mutate Silkie into a harbinger of doom. The two revealed themselves to stop him, but Killer Moth managed to mutate Silkie before they could attack. However, Silkie transformed into a nice mutant, causing Killer Moth to rant about his wasted savings. He revealed his intentions to go to bed and refused to give Silkie more tummy farts.
Teaching the Titans a lesson
Killer Moth plotted to take over Jump City by unleashing a giant pill bug on the city, but was confronted by the Teen Titans. He vowed that they would never stop him, but jumped off the pill bug to ask about Chuck, who the Titans believed was a newly transformed Beast Boy. Killer Moth noted that it didn't look like Beast Boy, and the Titans were appalled that he identified people based off their looks. He asked how else he was supposed to do it, and the Titans told him to focus on a person's insides. Killer Moth realized that the Titans were saying looks don't matter, and compared it to walking into a stinky bathroom and saying smells don't matter when they do. Robin said they wouldn't believe his lies, but Killer Moth protested that he's always been judged off his looks which is why he became a super villain. Starfire believed that he hadn't heard of "The Ugly Duckling", but Killer Moth pointed out that the duckling was only accepted once he became a swan. Raven deduced that Killer Moth was saying ugly things belong with each other and the Titans decided to leave him with Chuck to live a disgusting life together.
Killer Moth decided to teach the Titans a lesson and plotted to transform the entire population into disfigured insect humanoids. He faked an emergency distress call to the Titans to get them to his hideout and informed them of the Bug Beam's capabilities to mutate anyone's DNA. He zapped the Titans with the beam, and told them that since they all looked the same, looks truly do not matter. However, the Titans complained about their appearance and Killer Moth decided to abandon his plans to eradicate the unrealistic beauty standards imposed on society because the Titans failed to learn a lesson. He handed Chuck back to them and opted to go to bed. Robin asked for the antidote, but the villain refused.
Teen Titans Go! comic book series
Killer Moth was the second villain to arrive at the tower for the Titans' Party Party and informed them that he only attended to spend more time with Silkie. Throughout the party, he cuddled with the mutant moth larvae until Robin ordered all villains to leave, including Killer Moth.
Killer Moth attacked Jump City and told the Titans they were outmatched. He noticed Cyborg, who had been disguised, and asked about his identity. Beast Boy lied that he was their brand new Killer Robot Titan and asked Killer Moth if he wanted to see how he fared against one. The villain, however, immediately left.