Ringwraiths (Taurean Mauler)

Changeling (This creature is every creature type.)
Whenever an opponent cast a spell, you may put
a +1/+1 counter on Taurean Mauler.
They are the Nazguls, Ringwraiths. Neither living
nor dead. At all times, they feel the presence of the
Ring. Drawn to the power of the One, they will never
stop hunting you."
- Strider