Pestem Tenebris

When Pestem Tenebris enters the battlefield two target creatures get a -1/-1 counter.
Whenever a creature dies that had a -1/-1 counter create a 1/1 Black/Green Plague Crow creature token that has Flying, Wither and "This creature cannot have -1/-1 counters placed on it"
{b/g}{b/g}: Target creature gets a -1/-1 counter
{b/g}{b/g}{b/g}{b/g}: All other creatures get a -1/-1 counter