Durin's Bane

Durin's Bane costs {1} less to cast for each
creature your opponent's control.
{1}{r}, Sacrifice a creature: Durin's Bane gains
flying and trample until end of turn.

"Moria. You fear to go into those mines. The
dwarves delved too greedily and too deep. You know
what they awoke in the darkness of Khazad-dum:
shadow and flame." ~ Saruman the White