Activated abilities of creature cards in your graveyard cost less to activate.
Tap an untapped Zombie you control: Target player puts the top card of their library into their graveyard.
You canâ€™t normally activate abilities of cards in graveyards. Those that you can activate are those that instruct you to move the card out of a graveyard, or those that specifically say that you can activate them if the card is in your graveyard.
Any untapped Zombie you control can be tapped to pay the second abilityâ€™s activation cost, even one that just came under your control.
Activated abilities contain a colon. Theyâ€™re generally written â€œ[Cost]: [Effect].â€ Some keyword abilities (such as embalm) are activated abilities and will have colons in their reminder text.