Virus (Dr. Mario)

A Virus appeared in 1990 video game called Dr. Mario. A virus is a germ-based enemy found in the Dr. Mario series. Viruses most often appear in three colors – red, blue, and yellow – however, in later games in the series including Dr. Luigi and Dr. Mario World, a larger variety of colors and types are present. To defeat a virus, usually Dr. Mario must line up three Megavitamins of the same color next to the virus of that color. The virus, along with the Megavitamins, will then disappear. In most Dr. Mario games, after clearing one jar of viruses, Dr. Mario will move to the next one, with each jar containing increasingly more viruses.

Viruses come in five colors: red, blue, yellow, cyan and magenta. In most of their appearances, the red, blue and yellow viruses are bipedal, wear brown shoes and white gloves. In addition to their color, viruses can be distinguished by their appearances. Red viruses are the most distinctive, having floppy, round ears, two small horns that curve inward, yellow eyes, a mouth containing two teeth and a tongue, a spiked tail and a nose. According to the Tetris & Dr. Mario instruction manual, the red virus is female, making it the only one until the introduction of the magenta virus in Dr. Luigi. Blue viruses have large, spiked ears, no horns, yellow eyes, and a mouth containing a single tooth. Yellow viruses have two pairs of horns instead of ears, orange eyes, and no visible mouth. The cyan and magenta viruses lack legs and feet, yet also have distinct appearances: cyan viruses have large eyes with gold irises, two small antenna-like features on the top of their head, and a large mouth with four fangs and a long tongue. Magenta viruses have a square-shaped body with three small horns on the top of their head and slightly mottled skin, large eyes with eyelashes and magenta irises, segmented arms with mitten-like hands, and a large mouth with no visible teeth or tongue.

In the NES version of Dr. Mario, when the player beats the game with the level and speed set to 20 and high respectively, a cutscene will play showing a UFO flying over a tree with the three viruses, who then enter the UFO, hinting that they might be aliens of some sort. The UFO also appears before the title screen of Dr. Luigi.

Powers and Abilities
Viruses are contagious, to the point that one of them can multiply to fill an entire glass jar within seconds. According to the Nintendo Comics system, each virus has unique abilities that correspond with their names: red viruses can manipulate heat, blue viruses can manipulate cold, and yellow viruses can transform people into different shapes and species, which is referred to as "weirdness". In the Mario and Luigi series, viruses are able to change their color when attacked, and are shown to wield spears. Lining up four viruses of the same color using Megavitamins removes them.