Spawl, Phyrexian Elite

Spawl, Phyrexian Elite's power and toughness
are each equal to the number of creature cards
in your graveyard.
Whenever another creature you control deals
combat damage to a planeswalker or player,
sacrifice it unless it has a +1/+1 counter on it.
Mentor (Whenever this creature attacks, put
a +1/+1 counter on target attacking creature with
lesser power.)