Tithe Devourer

Trample, Vigilance, Lifelink
Tithe Devourer's power is equal to the number
of tax counters each opponent controls and
toughness equal to the number of tax counters
each opponent controls plus one.
At the beginning of each combat, you may
sacrifice three creatures. If you do,
Tithe Devourer gains double strike
until end of turn.