Knight of New Phyrexia

Whenever Knight of New Phyrexia attacks, put a -1/-1 counter on another target creature.
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Sacrifice Knight of New Phyrexia: Proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of a kind already there.)