Grove of the Guardian

Oracle Text

T: Add C.

3GW, T, Tap two untapped creatures you control, Sacrifice Grove of the Guardian: Create an 8/8 green and white Elemental creature token with vigilance.

Card Rulings

10/1/2012 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.
10/1/2012 You can’t tap Grove of the Guardian to activate both abilities at the same time.