In several Resident Evil games, the common crow has appeared as an enemy. In several incidents involving the T-virus, these carrion-feeders have become infected after feeding on smaller infected animals and even on zombie corpses. Unlike most other creatures, crows do not undergo such drastic mutations, the only physical difference between them and uninfected crows being a slight increase in size. The virus does heighten their aggression, however, and they will relentlessly attack any creature they feel threatened by, gathering in flocks and pecking enemies to death. During the Mansion Incident, S.T.A.R.S. member Forest Speyer was killed in this manner. The crows that killed him also passed on the T-virus, so he reanimated as a zombie.
Since the Raccoon City Destruction Incident, there have been no further reports of crows becoming infected with the T-virus.