Phroentia, Sister of Nature

Indestructible, Faith(This creature can't attack or
block unless your total devotion is 10.)
At the beginning of your upkeep, put a +1/+1
counter on target creature.
Whenever a creature deals combat damage to a
player, put that many +1/+1 counters on a
creature you control.
Serpents are her preferred worshipers.