The Legion of Doom (do not confuse with another evil organisation of the same name) are one-time villain protagonists of Teen Titans Go! episode "Snuggle Time". They are the Teen Titans who became villains to have more free time.
The Titans were relaxing at their base when a crime alert came to them. Annoyed, they set off to check the case. They realize that HIVE were attacking the museum with a death laser. Thinking they are having fun, Teen Titans use the laser themselves. After that, they decide to become villains: they change their appearance, steal Legion of Doom's name, hire henchmen, build an evil lair, kill Batman, Batgirl and Titans East. After that, they continue to cause destruction and plan to bomb the Earth with stink bombs. Suddenly, the crime alert goes to HIVE,who are disgusted by the Legion's crimes and think they do this to teach the actual villains a lesson. Robin, however, explains they are doing bad stuff because it's fun. After that, they cover the Earth in a wrap and launch stink bombs, presumably killing everyone on the planet.
Robin's villainous identity bearing a resemblance to both his voice actor Scott Menville and Lex Luthor. While he used to be a leader of Teen Titans, he had shown his villainous nature to be more contrast to his good self in comparison with his teammates.
Beast Boy's villainous identity. Bears a resemblance to Killer Croc and Solomon Grundy. He and The Cyborg plan to streak in front of women and kids.
Cyborg's villainous identity. The only change in design is spikes added to his body parts and the only change in name is putting "The" at the beginning.
Starfire the Terrible
Starfire's evil alter-ego previously appeared in an episode of the same name, except she became a villain to help Robin get an arch-nemesis. However, her role in the episode "Snuggle Time" is less sympathetic. She plans to steal all rabbits in the world.
Demon of Azarath
Raven's evil alter-ego. As a hero,she resembled a generic female Tamaranian, but Demon of Azarath's design resembles her father more. She is more serious than her teammates and offers a plan to manipulate the world via politicians and mass media. Her plan, however, is rejected for being boring.
Henchmen are, as their name suggests, they are goons of the Legion of Doom that do all the dirty jobs while their commanders relax or do villainous stuff. Their uniform resembles that of HYDRA soldiers.