Clam-digger

For over a year he had been beating his way along the south shore of Lake Superior as a clam-digger and a salmon-fisher or in any other capacity that brought him food and bed.

Source: wiktionary

[T]here was no funeral cortege, naturally, there being no mourners other than myself and Mr. Spitzer and the old, clammish clam-digger chauffeur who drove the rickety Packard with the storm curtains and roof through which the rain fell, […]

Source: wiktionary

His father made a living as a clam-digger. For some reason, probably out of his own feelings of low status, he kept telling young Vincent: “You’re a dummy! You’ll never amount to anything more than a clam-digger’s son.”

Source: wiktionary