Streptococcus agalactiae

Infect
When Streptococcus agalactiae enters the battlefield, put up to three -1/-1
counters on any number of target
creatures your opponents control.
When a creature with a -1/-1 counter dies,
put a +1/+1 counter on Streptococcus agalactiae.
At the beginning of your end step, proliferate.
Virulence is a lifestyle.