Creature — Cat
2 / 3
Trample
When this creature enters, you get

(an energy counter).
Whenever this creature attacks, you may pay

. If you do, it gets +2/+0 until end of turn.
Some triggered abilities state that you "may pay" a certain amount of
. You can't pay that amount multiple times to multiply the effect. You simply choose whether or not to pay that amount of
as the ability resolves.