Conjoined twins a single fertilized egg does not fully split during the process of forming identical twins. The second theory is that a fusion of two fertilized eggs occurs earlier in development. Although conjoined twinning has not been linked to any environmental or genetic cause, they occur so rarely it has not been possible to draw firm conclusions. Surgery to separate conjoined twins may range from very easy to very difficult depending on the point of attachment and the internal parts that are shared. Most cases of separation are extremely risky and life-threatening. In many cases, the surgery results in the death
Trigger Twins Secret Society of Super Villains. As part of an army, they are sent to destroy the city of Metropolis. Another army of superheroes face them. During what is called "Battle of Metropolis", the twins are shot down in the street by a group of vigilantes that include the current Vigilante and Wild Dog who were perched on a nearby rooftop. This battle takes place in "Infinite Crisis" #7. During the "Blackest Night" crossover, the Trigger Twins are among the many deceased villains that receive a black power ring, reanimating them into Black Lanterns. The Earth 18 version of Trigger Twins