|Hey, aren't you that plant lady, Poison Oaky?|
The Superman Revenge Squad was a group of supervillains who formed a pact to destroy Superman. They attacked Metropolis, intending to lure Superman into a trap where he would be destroyed by a disintegrator beam invented by Toyman.
The attack was only partially successful: the villains managed to hold the rest of the Justice League at bay, but Toyman was only able to hit Superman by tricking him into throwing himself in front of the beam to protect Batman and Wonder Woman. After his disappearance, the villains were defeated and taken into custody, though Livewire and Kalibak subsequently escaped prison and attacked Metropolis again (along with other criminals including Star Sapphire, Deadshot, Volcana, and Copperhead) in "celebration" of Superman's death.
Unknown to any of them, Superman had not been destroyed, only sent into the future.
Though the group is never named on the series, it is an obvious homage to the Superman Revenge Squad from DC Comics, who likewise sealed their pact by stabbing knives into a representation of Superman's sign. The title of this article is conjecture based on these similarities.