Whenever equipped creature attacks, defending player reveals cards from the top of their library until they reveal a land card. The creature gets +1/+0 until end of turn for each card revealed this way. That player puts the revealed cards into their graveyard.
11/17/2017 The land card is counted when calculating the bonus, and it will be put into the graveyard with the other revealed cards.
11/17/2017 If the equipped creature is attacking a planeswalker, the controller of the planeswalker is the defending player.