Evolution Chamber

Zerg Creatures you control get +X/+X, where
X is the number of evolution counters on
Evolution Chamber. Evolution Chamber cannot
have more than three evolution counters.
{t}: Add one mana of any color. Spend this mana
only to cast Zerg spells or activate abilities of
Zerg permanents you control.
{1}{g}{t}: Put an evolution counter on Evolution Chamber.