Plague

Member of the Horsemen of the Apocalypse.

The four horseman are Apocalypse personal warriors and always play a key role in his plans for mutant conquest and domination. They consist of Death, War, Famine, and Pestilence. The enhancements made to horseman are often a combination of both biological or genetic manipulation and the employment of the celestial technology that Apocalypse uses.
 
Plague was an elderly woman with the power to absorb any disease near her, and then release an amplified form of the infection through skin to skin contact. She uses her ability to kill many people before being stopped by the Power Pack.  

Plague died in the X-Factor book during a confrontation with Power Pack when she was knocked from her mechanical horse and fell to the ground.