Selvin, Mandible's Second

Firststrike, Trample, Vigilance
When Selvin, Mandible's Second enters the battlefield and at the beginning of each player's upkeep, put a +1/+1 counter on a number of
armies you control equal to Selvin's power.
Armies you control have "{t}: Tap target creature
with power equal to or greater than this creatures
power."