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.
1 If you're going to breed them artificially, no plants are necessary, although they do improve quality of life (and act as a great water filter) when the fish are not breeding. 2  Consider investing in spawning mops. 3  Spawning mops are made of floating nylon string into which females send their eggs.