Scraptrawler

This card costs {2} less to cast for each
creature card milled this turn.
Whenever a creature card is milled, you may
return a creature card with converted mana X
or less milled this way to the battlefield under
your control, where X is Scraptrawler's power,
then put a +1/+1 counter on Scraptrawler.
This ability triggers only during your turn
and only once each turn.