Craniopagus twins of the twins have outside the womb. Relatively few craniopagus twins survive the perinatal period – approximately 40% of conjoined twins are stillborn and an additional 33% die within the immediate perinatal period, usually from organ abnormalities and failure. However 25% of craniopagus twins survive and can be considered for a surgical separation and several attempts occur yearly worldwide. In the last-half century, many advances in medicine including brain imaging, neuro-anesthesia and neurosurgical techniques have proven that a successful outcome is possible following separation of total craniopagus twins. There are two categories of craniopagus twins: The exact nature of how
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