Devouring Parasite

Whenever Devouring Parasite attacks, place a
counter on defending creature. If that creature
gets 3 counters, it dies.
Whenever Devouring Parasite is sent to the graveyard, place two 1/2 black Parasite tokens on
the field with the ability "When this creature
attacks, place a counter on defending creature. If
that creature gets 3 counters, it dies."