Virus

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 Capsule pieces of the same color next to the virus of that color. The virus, along with the capsules, 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.

Dr. Mario


Viruses first appeared in the NES and Game Boy game Dr. Mario, where they are small germs that Dr. Mario must eliminate. To do this, he uses vitamin capsules, which can come in combinations of their colors (red, blue, and yellow), four of these capsule pieces must be stacked on top of a virus of the same color to eliminate it. As the difficulty increases, the number of viruses will also increase.

In the Game Boy version due to the system being incapable of displaying bright colors, viruses appear in black, white, and gray. The black virus resembles the red virus, the gray virus resembles the blue virus and the white virus resembles the yellow virus. Because the simple monochrome display of the Game Boy is only able to show a few shades of gray, the black and gray viruses lack the black sclera that the red and blue viruses had, and hence look marginally different. In the high-level ending, the viruses are seen on a tree before being beamed up by a UFO.

They are found in the remakes Tetris & Dr. Mario and Dr. Mario & Puzzle League for the Super Nintendo Entertainment System and Game Boy Advance respectively.

Dr. Mario 64
Viruses appear again in Dr. Mario 64, and they play the same role as before. The way to beat them stays the same, too. Dr. Mario 64 adds a Flash mode, where one virus of each color is flashing, and two players compete to clear the flashing viruses with numerous other viruses in the way.

Dr. Mario Online Rx


Viruses also appear in the WiiWare game Dr. Mario Online Rx, where they act like they do in Dr. Mario. They are also seen fighting Miis in the Virus Buster game.

Dr. Luigi
Three new viruses with two new virus colors, cyan and magenta, appear in the Wii U game, Dr. Luigi, exclusive to the Nintendo eShop. The classic blue, red, and yellow viruses appear in the "Retro Remedy" mode by default, while new viruses – a cyan virus (Dizzy), a magenta virus (Confused), and an alternative yellow virus (Drowsy) – appear in the new Operation L mode by default. The colors of the viruses in this game are based off colors.

Dr. Mario: Miracle Cure
The standard three viruses return in Dr. Mario: Miracle Cure, in the same role as past games. Even though Dr. Luigi and the Operation L gameplay return in this game, the new viruses seen in Dr. Luigi do not.

Dr. Mario World
The standard three viruses returned in Dr. Mario World, along with four new green, purple, light-blue, and pink viruses. The three classic viruses also received a new design reminiscent of their in-game appearance from Dr. Mario, and were prominently featured in the promotional video series for the game, Virus Vid. Although there were seven types of viruses, they did not appear in all stages. In the regular stages, three out of red, blue, yellow, green and light-blue would appear throughout that World. Pink viruses exclusively appeared in challenge stages and special stages. Purple viruses were absent in stages and only appeared on the world map.

Viruses could come with new gimmicks in Dr. Mario World, such as being frozen in ice, encased in bubbles, protected by cages that could be unlocked with lock blocks, or hidden by clouds and dust. A variant called the floatie virus could teleport away from a matched pill to another location on the grid. Unlike the other Dr. Mario games where a match of four in a row or column involving capsules are required to eliminate them, the viruses in this game required a capsule match of three in a row or column to eliminate (such as two viruses and one capsule piece of matching color).

Nintendo Comics System
The viruses appear as the main antagonists in Nintendo Comics System's adaptation of Dr. Mario entitled "The Doctor Is In... Over His Head". This appearance names the red virus Fever, the blue virus Chill, and the yellow virus Weird.

In the same comic, the viruses are given special powers: Chill can manipulate the cold, Fever can control heat, and Weird can forcibly morph others into different shapes and creatures.

Club Nintendo
Two viruses can briefly be seen inside Bowser's stomach in the Club Nintendo comic "Süße Weihnachten". They symbolize his sickness after having eaten too much.

Super Smash Bros. Melee
The viruses appear in Super Smash Bros. Melee as a trophy, which can be obtained when it appears at random in one of the game's single-player modes.

Super Smash Bros. Brawl
In Super Smash Bros. Brawl, each of the blue, red and yellow viruses are featured as separate stickers. They can be used in The Subspace Emissary by any fighter. The blue virus sticker boosts electric attacks by 5 points, the red virus sticker boosts fire-based attacks by 20 points and the yellow sticker increases the amount of damage recovered after eating food by 4 points.

Super Smash Bros. for Wii U
The viruses are featured as a trophy in Super Smash Bros. for Wii U. The trophy can be collected once it appears at random in one of the single-player modes, such as Vs. mode and others.

Super Smash Bros. Ultimate
The viruses appear in Super Smash Bros. Ultimate as an Advanced-class support spirit that occupies one support slot. Upon use, the spirit reduces the damage taken from poison-based attacks. In World of Light, the spirit is encountered on the Light Realm map near Riki's Dojo. The spirit's puppet fighters are three Kirbys, each colored after one of the viruses, and the battle takes place on the Battlefield version of the Mario Bros. stage.

WarioWare series
In WarioWare, Inc.: Mega Microgame$!, one of 9-Volt's microgames called Dr. Mario is based on the game Dr. Mario, and the player must defeat the viruses using capsules, just like in the game. There is also a minigame in the same game called Dr. Wario, which is a Wario version of Dr. Mario, where the viruses look different. In WarioWare: Twisted! in the microgame Weird Science, a blue virus makes an appearance. WarioWare Gold features another Dr. Mario microgame under the same name, where the player must tilt the game system to defeat a row of three Viruses.

Mario & Luigi: Superstar Saga / Mario & Luigi: Superstar Saga + Bowser's Minions
Viruses appear as enemies at Woohoo Hooniversity in Mario & Luigi: Superstar Saga and its Nintendo 3DS remake, Mario & Luigi: Superstar Saga + Bowser's Minions. They appear in all three colors and attack in groups. When hit by Mario or Luigi, they will change into a different color. When a red virus is hit, it will become a blue virus; when a blue virus is hit, it will become a yellow virus; and when a yellow virus is hit, it will become a red virus. Once all viruses in-battle match in color, they will be instantly destroyed, which is a callback to how they were destroyed in Dr. Mario. Additionally in the remake, when three of them are defeated at once, a small portion of the "Fever" theme plays as well. Viruses attack by charging at Mario or Luigi and chewing on their heads, which can be countered by using the hammer. Sometimes when a brother fails to counter this attack, he will be poisoned. Each color has different stats; for example, red viruses have the highest POW and lowest DEF. Additionally, thunder-based and fire-based attacks will do critical damage to red and blue viruses, respectively, though a yellow virus will be healed when hit with either element. When using an Advanced Swing Bros. attack against a yellow virus or defeating it with the Game Boy Horror SP equipped, it will drop a Steady Badge.

Mario & Luigi: Bowser's Inside Story / Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey
The blue virus makes a cameo in Mario & Luigi: Bowser's Inside Story and its Nintendo 3DS remake, Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey. After knocking out all the body segments of a Toothy, the Toothy attacks by spitting out a blue virus holding a small spear to attack the player.

In the Toadley Clinic's lobby, there is a on the wall featuring a blue virus.

Mario & Luigi: Dream Team
Viruses appear in Mario & Luigi: Dream Team as enemies during the Ultibed part hunt. In the field, viruses chase Mario and Luigi upon sight. Viruses also change color whenever they are damaged (with the exception of counter-attacks); much like how they did in Mario & Luigi: Superstar Saga. The pattern they go in is from blue to yellow to red and back to blue again, repeating itself. The player can connect three or more of the same color to make them disappear, defeating the connected viruses instantly, also like in Mario & Luigi: Superstar Saga. If a virus is defeated, the ones behind it will move forward to the front if possible. They always appear in a group of 16, which is the most enemies seen in a battle in the real world. They are also one of the very few enemies who can inflict the Mini status on the Bros. which decreases their Attack and Defense and shrinks them.

Viruses may attack by forming two lines, one in the foreground and one in the background, and proceeding to move several steps in any direction each time. This can be dodged by jumping when appropriate. Viruses may also attack by circling the Bros. in a single file line, Mario and Luigi then having to hammer them all into a pile before they attack them after circling several times. If three of the same color land on the pile consecutively, they disappear like they would normally. If they are jumped on, they change color twice and if the hammer is used they will change color once. When combined with Mini and DEF-Down, the damage dealt by a virus to the Bro can easily turn into a one-hit KO (999+ damage) without enough points in Defense; this can essentially end the game very quickly. Red viruses can inflict POW-Down, yellow viruses can inflict DEF-Down, and blue viruses can inflict SPD-Down

Mario Kart Arcade GP series
In the Mario Kart Arcade GP series (including GP 2 and GP DX), there are two blue Virus related items: Wheel Virus and Dizziness Virus. The first and third titles include both, while the second only has the Dizziness Virus.

Mario Kart Tour
The red, blue, and yellow viruses from Dr. Mario World return in Mario Kart Tour on a glider that debuts in the Doctor Tour.

Nintendo Puzzle Collection
The Viruses reappeared in the Dr. Mario game (a close remake of Dr. Mario 64) of Nintendo Puzzle Collection.

Other appearances and cameos
Viruses appear as enemies in the unlockable minigame Virus Buster (also known as Germ Buster) for Brain Age 2: More Training in Minutes a Day!, which was later included in Dr. Mario Online Rx and all subsequent titles in the Brain Age series.

Viruses also make a small cameo in the obscure Super Famicom game Motoko-chan no Wonder Kitchen, appearing in a cut-scene for mayonnaise 'facts'. They also cameo in Nintendo Monopoly, appearing on one of the Coin Block (Community Chest) cards. Viruses are also referenced in Super Paper Mario when a Shayde says he was killed for an illness caused by multicolored viruses. Of all the virus colors, the blue virus is the one with the most appearances and cameos.

As part of the promotion for the release of Dr. Mario World, three T-shirts modeled after the main three viruses were released on July 19, 2019 as a gift in Animal Crossing: Pocket Camp.

Physical description
The design of the various viruses has changed somewhat over time. In most of their appearances, viruses are bipedal and wear brown shoes and white gloves. Depending on the media, some viruses are missing certain limbs, and in some appearances, can even have floating extremities. Viruses come in multiple colors, each with a unique set of physical characteristics to set them apart.

The three viruses featured in the original Dr. Mario for NES have appeared in far more entries than others and have had the greatest revision in terms of design. Red viruses have yellow eyes, large buck-teeth, an outstretched tongue, round pill-shaped ears, and a pair of horns, with earlier depictions giving them floppier dog-like ears, thinner horns, a simple nose, and a spiked tail. 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 Confused in Dr. Luigi. Blue viruses have yellow eyes, thin stemmed eyebrows, no horns, and a single tooth, with earlier depictions rendering their eyebrows as spiked ears that wrap around the back of the head instead. Yellow viruses have orange eyes, two pairs of horns, a pronounced eyebrow ridge, and a unique snout-like nose with jowls, with earlier depictions typically having the eyes be smaller and uneven in size.

Viruses introduced in Dr. Luigi are vastly different in appearance from the others, lacking gloves on their hands and feet entirely. Cyan viruses are spherical and have large white eyes with gold irises, two small bulbous antennae on the top of their head, and a large mouth with four fangs and a long tongue. Magenta viruses have a cube-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 square mouth with no visible teeth or tongue. The alternate yellow virus has a blob-like appearance, large eyes with green irises and droopy eyelids, a single spike protruding from the top of its head, low-hanging fork-shaped arms, and a long mouth featuring a line of teeth on the lower jaw.

Viruses introduced in Dr. Mario World share many design elements with the original three viruses, however, they all now have a more super-deformed appearance and noticeably lack arms. Green viruses have yellow eyes, two large leaf-like features atop its head, no teeth, and a sad or sick expression. Pink viruses have yellow eyes, a single bulb-like antenna atop its head, and a fixed wide grin with large puffed-out cheeks. Light-blue viruses are most similar in appearance to the original yellow viruses, though they have a lower eyebrow ridge, three horns instead of four, and a wide frown with a single tooth sticking up. Purple viruses have yellow eyes, a wide mouth with a single tooth off to the side on the upper jaw, and a single horn protruding from the front of the head.

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.

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 capsules removes them.

Personalities and relationships
Throughout the Dr. Mario series, the viruses are shown to be mischievous and invasive. Three individual viruses—namely, Red, Blue, and Yellow, each representative of a virus color—are further characterized in promotional material for Dr. Mario World; for instance, the Virus Vid series often portrays them as being too bumbling and incompetent to cooperate towards a common goal ("they never seem to get together"), though being otherwise fond of each other's company ("…but they do seem to get along, somehow"). The official Dr. Mario World Twitter and Facebook accounts, where announcements and updates related to the game are communicated in person by the aforementioned three viruses, present a number of quips that reveal more particularities about their character. Yellow is shown to have a proclivity for snacks and a tendency to daydream and prattle about wings,  to Red's bemusement. Red secretly wishes to be popular, and when Yellow makes his secret public, he does not object, confidently stating that he is already popular due to his "eye-catching color". In addition, Blue suggests that Red is a poor planner.

Red, Blue, and Yellow are not gregarious with other characters. In their above-mentioned social media presence, they often express fear when announcing the arrival of a new doctor, uttering pleas such as "Please take it easy on me". In a June 12, 2020 post, Yellow announced an in-game event where 20 of the then-available 21 doctors had their staffing rates increased by 1.5, with the omitted doctor being Dr. Waluigi ; the virus indicates in the post that said doctor was left out because they particularly do not get along.