Wendigo

As an additional cost to cast this creature you
must sacrifice a creature. Wendigo have +x/+x
where x is equal to the sacrificed creature's
toughness.
Each upkeep, sacrifice a +1/+1 counter on any creature or lose 2 life.
Intimidate, Trample, Attrition (When this creature
deal damage to a player, mill this opponent deck until
you put a creature card into his graveyard.)