A zombie is identified by its mindlessness, sluggish movement, slurred speech and hunger for human flesh or brains. Zombies usually appear to be dead humans, visually displaying decaying flesh, missing body parts and bloodstains. Zombies often wear torn clothing and exhibit immortal-like qualities. They are often only able to be killed by means of beheading.
Zombies are fictional beings. Humans who truly act like zombies typically suffer from a disease, such as sleeping sickness, that features zombie-like symptoms. Sleeping sickness is the result of a brain parasite that renders the victim sleepy, irritable and hungry. They are often unable to eat, speak with slurred speech and experience itching. Victims eventually succumb to a coma, then death. The disease has been more prevalent than the AIDS virus in some areas of the world, such as Uganda.
Other cases of zombie-like behavior have been attributed to the consumption of a drug found in bath salts called methylenedioxypyrovalerone. Some symptoms related to consuming bath salts have included insomnia, psychosis and even violent behavior that leads to cannibalism. Abusers of bath salts often experience hallucinations and have exhibited superhuman strength and paranoia. The drug can be smoked, snorted or injected for a high, causing the zombie-like behavior as a side effect.