Parasitic twin formed or wholly dependent on the body functions of the complete fetus. The independent twin is called the autosite. Parasitic twin A parasitic twin (also known as an asymmetrical or unequal conjoined twin) is the result of the processes that also produce vanishing twins and conjoined twins, and may represent a continuum between the two. Parasitic twins occur when a twin embryo begins developing in utero, but the pair does not fully separate, and one embryo maintains dominant development at the expense of its twin. Unlike conjoined twins, one ceases development during gestation and is vestigial to a mostly fully
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