Cliodhna, Death's Eminence

Deathtouch
Whenever a creature you control with deathtouch
deals damage to a player or planeswalker, put a
+1/+1 counter on that creature.
{b/g}{b}{g}, {t}: Create a 1/1 black and green Spirit Assassin creature token with deathtouch and "Whenever this creature deals damage to a planeswalker, destroy that planeswalker."