Glistening Extractor

Glistening Extractor enters the battlefield
with four oil counters on it.
At the beginning of your upkeep, if there
are one or more oil counters on Glistening
Extractor, Seek a card with mana value
equal to the number of oil counters on
Glistening Extractor, then remove an oil
counter from Glistening Extractor.