Koh, the Face Stealer

Fear (This creature can't be blocked except by
artifact creatures and/or black creatures.)
Whenever a creature card is put into an
opponent's graveyard from anywhere, you may
have Koh, the Face Stealer become a copy of
that card, except its name is Koh, the Face
Stealer, it's legendary in addition to its other
types, and it has fear and this ability.