Examples from the Web for croaker
The easiest way to convince a croaker to write a “script” for morphine is to fake gallstones or kidney stones.American Dreams, 1953: ‘Junky’ by William S. Burroughs|Nathaniel Rich|June 27, 2013|DAILY BEAST
"My sister-in-law says you are a croaker, Charlotte; and she's right," cried Caroline Mason, with good-humour.Mrs. Halliburton's Troubles|Mrs. Henry Wood
Bascom and Captain Lazaré's boy Narcisse were diving near the croaker bank.
Thirty-five of them appeared over the signature of Croaker, from which they became known as the Croaker Papers.A History of American Literature|Percy H. Boynton
British Dictionary definitions for croaker
Word Origin and History for croaker
"prophet of evil," 1630s, agent noun from croak (v.); a reference to the raven (cf. Middle English crake "a raven," early 14c., from Old Norse kraka "crow," of imitative origin).