The Carla Spores were bizarre manifestions of Carla Radames (and therefore Ada Wong) after she had infected herself with the C-Virus. Appearing identical to the "real" Carla shortly after infection, they represented Carla's growing mental instability.^[1] These Spores were used by Carla to confront Ada Wong in a more personal manner, as opposed to using her increasingly-dehumanized body.^[2]

Sources

1. ↑ Capcom. Resident Evil 6. (Capcom Co., Ltd.). File: Unlimited Transformation.
2. ↑ Capcom. Resident Evil 6. (Capcom Co., Ltd.). Level/area: Ada Chapter 4.