Zombies are humans resurrected from the dead, mostly due to T-Virus infection. Symptoms of the T-Virus include mutation and progressive skin decay. They are known as "Zombies" due to their grotesque, corpse-like appearance. They wander in search of human flesh, their only source of nutrition, as they constantly require vast amounts of energy to sustain the sudden increase in metabolic demand. Although small amounts of damage will not deter a Zombie, they can be terminated by destroying the head.
The Zombies featured in RE1 are among the most well-known, but there are many different types of Zombie such as the Zombie cops and the "sexy" tank top-wearing Zombie girls in RE2. Characters like Edward, Forest, and Brad from S.T.A.R.S. are also zombified. Steve, in Code Veronica, is tragically forced to gun down his own zombified father in perhaps what is one of the most emotional scenes in the series.