griper

noun

1. One who gripes.
2. (archaic)An oppressor or extortioner.

   “She did Accept of our intended Present, which (she said) manifested our Love and Loyalty; most graciously affirming, That She was never any greedy Griper, or fast Holder; and what We did present, She would not hoard up; but Our Eyes should see the Bestowing of it.”

   “[…] there wanted not those who condemned his pride and hypocrisy, knowing Pandulphus to be a most greedy griper, as appeared by his unconscionable oppression in the bishopric of Norwich, which was afterwards bestowed upon him.”

   “When Southey's sackbut tunes the praise Of every Royal griper, Or any Minister, whose pipe Takes part in measures rotten ripe, While England pays the piper!”