Green zombies are irregular mutations that appear in the game Resident Evil Outbreak. They are human T-Virus victims that have been infested by some manner of infected plant. What kind of plants they were before T-Virus infection is unknown, but they have taken on a parasitic nature and now use the zombies as vehicles in order to spread their spores.
Green zombies behave just like regular zombies, shambling about clumsily as they seek out living flesh to consume. While zombies pose enough danger by spreading the T-Virus through their saliva, green zombies also scatter toxic spores produced by the plant bulbs emerging from their heads.
Green zombies possess the same weaknesses as regular zombies, though they will also release spores from their bodies whenever they are struck. The only way to kill them without releasing the spores is to douse them with a green chemical that will neutralise the plant toxins.