Mallow, Marshmarcher Overlord

Trample
Whenever a creature enters the battlefield under
your control, you may pay {x}{w}{p/w}. If you do,
create a 1/1 Marshmarcher token with X +1/+1 counters.
Mallow, Marshmarcher Overlords power and toughness are equal to the amount of
Marshmarchers on the battlefield under your
control, plus two.