Infected adders appear as enemies in the first Resident Evil game and its remake. These small serpents were encountered by the Special Tactics & Rescue Squad during the Mansion Incident, most notably in the courtyard area between the Spencer Mansion and Dormitory. These creatures were not a part of Umbrella's research but ordinary snakes native to the Arklay Mountains that were infected when the T-virus was scattered over the area. The virus' effects on the adders appears to be minimal; there is no malformation or size increase, but the creatures' aggression has been heightened as has the potency of their venom. Humans bitten by these snakes will die in a matter of minutes, and since the poison also carries the T-virus, victims will also turn into zombies shortly after death.