Twitch, The Plague Rat

Deathtouch, Infect (This creature deals damage
to creatures in the form of -1/-1 counters
and to players in the form of poison counters.)
{b/g}{b/g}{b/g} {t} Target Rat gains deathtouch
and infect until end of turn
{2}{b/g} {t} Deal 3 damage to target non-black
or non-green creature