Certain spells and creature abilities target other creatures.
Whenever you use a spell or creature ability that says to do something to a target, you choose the target for that ability. You can only targetcreatures that are in the battle zone (unless otherwise stated).
Examples of cards that target
As these cards use the word target, they do target.
When this creature enters the battle zone, you may put the top 3 cards of your deck into your discard pile. For each Darkness card put into your discard pile this way, your opponent chooses one of his or her creatures in the battle zone. Banish those creatures.