Chimera are created by inseminating a human ovum with fly DNA, through the use of the t-Virus as a bonding agent. The egg is then inserted into the uterus of a human where it matures. As Chimeras grow at the speed of flies, the infant would likely take only a day to be born. After birth it takes approximately 2–4 days to reach adulthood.[excerpt 1]
Aside from their fly-like appearance, the Chimera's most notable characteristics are their ability to walk on walls and ceilings. They usually use the air ducts to travel from one part of the lab to the other and attack with their claw-like limbs. When killed, a chemical imbalance in their bodies causes them to dissolve.
They cannot fly because of the lack of size of their wings, and they lacked a fully developed exoskeleton. Even though they showed signs of notable resilience, their intelligence was little more than that of an insect. Their bodies also hosted a large number of maggots.