This guy's kind of like Ulvenwald Tracker except better in most situations. The biggest flaw with Ulvenwald Tracker is that is usually requires a big creature in order to be effective. Even if you put a Basilisk Collar or a Sword of Kaldra on the Tracker himself, he's going to die upon resolution. This card, on the other hand, won't die if the targeted creature no longer exists after it's dealt damage. It's that crucial split in the middle of the ability that makes all the difference. Now, this card is a smidge more expensive than Ulvenwald Tracker, but for slower format like EDH, it's a great source of creature removal in green if used with the right cards. Despite that, it's still a pretty good card.
Pros: Doesn't receive damage if other creature isn't there to deal it
Cons: Slightly expensive when compared to Ulvenwald Tracker, requires another card