CLOSE RELATIVES: None.
SKILLS AND ATTACKS: Bite.
STRENGTHS: Has three forms, decent attack strength.
WEAKNESSES: They'll be instantly defeated if you match three of the same color.
BACKGROUND: Originally thought to be exterminated by Dr. Mario, the viruses were recently discovered to have survived in the far-off Beanbean Kingdom. They tend to attack in groups and never fight alone. It is unknown how the Viruses became large (as before, they could only been seen at microscopic scale in bottles), but reports claim that Cackletta used her magic on a bottle containing the last specimens. They quickly duplicated and took over the lab alongside Laser Snifits and Mecha-Chomps. Viruses have the ability to shift their form between the three colours when attacked, read the Battle Plan for more info.
EVOLUTION: In Dr. Mario, they appeared as small and 8-Bit style. Returning to Mario & Luigi, they were larger and had more distinct facial expressions.