Virus is a microscopic organism that lives in a cell of another living thing. Although viruses are extremely small and simple, they are a major cause of disease. Some viruses infect human beings with such diseases as measles, influenza, and the common cold.
Passive Mobs. Passive mobs are composed of creatures that will never, under any circumstances, attack the player. Some passive mobs can be bred to create more of them, e.g. pigs can be bred to effectively farm them.
Many breeds have a standard for brindles. Boxers, one of the most common examples, have only two true colors: fawn and brindle. For any brindle breed, reverse brindling is possible. Some refer to the heavy brindling that produces a dog to be almost black as sealed brindling, but this term is not standard.