Finally, a creature that I don't think anyone can complain about. Timmies, Johnnies, and Spikes will all rally to its cause:
This is a card begging to be broken. It'll fit right in with the existing Innistrad Block UG self-mill deck that's already very story, but this card is so strong that it has the potential to make a mark in other formats as well. It's basically asking for someone to find a deck that can cast a 10/10 creature for one green mana consistently. If that deck is ever found, Ghoultree is going to see a lot of play.
This is another Dark Ascension zombie that might be able to find its way into my existing Innistrad Constructed BUG Zombies deck. Together with Gravecrawler, my deck is definitely going to get a face-lift once the full Dark Ascension set is spoiled.