Canada

You may play Canada whenever an opponent could play a land.
Canada enters the battlefield tapped.
As Canada enters the battlefield return an untapped land you control to your hand.
{t}: Add {w}{u}{b}{r}{g}.
{1}, {t}: Put a maple leaf counter on Canada.
{5}, {t}: Create X 5/5 green moose creature tokens with trample where X is the number of maple leaf counters on Canada.