Not a bad little card. It's either a chump blocker that gives you mana for that Terror in your hand or it sticks around for a turn to accelerate you by 2 mana for that Crypt Angel you're going to draw on turn 3. It's basically just mana storage, which can be very useful for slamming big drops early game. The only problem I really have with it is that it has to tap, meaning it has to stay alive for a turn, otherwise you'll lose your investment. Still, pretty good for 2 black.
Pros: Early mana storage
Cons: Has to tap, usable only once