Grove of the Guardian
Land
{T}: Add {1} to your mana pool.
{3}{G}{W}, {T}, Tap two untapped creatures you control, Sacrifice Grove of the Guardian: Put an 8/8 green and white Elemental creature token with vigilance onto the battlefield.

* To activate Grove of the Guardian’s second ability you can tap any two untapped creatures you control, including ones you haven’t controlled continuously since the beginning of your most recent turn.

* You can’t tap Grove of the Guardian to activate both abilities at the same time.