Medusa

When Medusa is turned face up, turn all
attacking creatures to stone. (Stoned creatures can't attack, are stone creatures, and have no other rules
text.)
{w/b}{w/b}, {t}: Turn target creature to stone.
Morph {w}{b}{b}(You may cast this card face
down as a 2/2 creature for {3}. Turn it face up any
time for its morph cost.)