You have the mana cost incorrect. It actually costs

{G}{G}, putting it in the same league as Blastoderm, Hunted Wumpus, or Emperor Crocodile. Among them, I think it is possibly the best of the lot. Its drawback is definitely less strict than Hunted Wumpus's and unlike any of the others, it has trample. Although it is Legendary, which could be annoying from time to time, it is also a 5/5 creature, which means that it shouldn't take too longer after it hits the table for you to win. There should not be enough time to draw into a second one.