Albizia Tree

Albizia Tree starts with 4 +1/+1 counters on it.
{t}, Flip a coin: If the coin comes up heads,
remove a +1/+1 counter and put a -1/-1
counter on target creature if that creature's controller controls a forest.
{t}: add {g} to your mana pool.
{t}, {2}: Search your library for a Forest and put it
on the battlefield tapped.