Awaken the Sentinel

At the beginning of your upkeep, gain 1 life.
{g}: If Awaken the Sentinel is not a creature it becomes a 0/3 Green Construct creature with Reach until end of turn then put a +1/+1 counter on it. If it's toughness is 7 or greater, it becomes a creature with Reach permanently.
A little bit of mana can go a long way.