The Infected Bat (インフェクティッドバット,infekutiddo-batto?) is a rare mutation within bats that have already been infected with t-Virus. Their main distinction is their enlarged size, which is unusual for mammalian mutants. They are also capable of summoning other bats nearby with piercing screeches.
One of these bats emerged during the t-Virus outbreak at the Umbrella Executive Training School, and made the chapel its home. This bat was killed on the night of 23–24 July by S.T.A.R.S. officer Rebecca Chambers and Billy Coen. A second Infected Bat was encountered by Albert Wesker during the 2003 Caucasus Laboratory Incident.