crib-biter, n. — Green’s Dictionary of Slang

crib-biter n.

[SE crib-biter, a horse that bites the metal crib in which its fodder is placed]

a grumbler.

1831		Observer (London) 13 Mar. 3/2: Sir R. Peel was a crib-biter, who did not gulp down arguments, but nibbled them.
1850		Tennessean (Nashville, TN) 3 June 2/1: The Union, adopting the suggestion of some disappointed and embittered ‘crib-biter’ [...] proposes [etc].
1860		Hotten Dict. of Modern Sl. etc. (2nd edn).
1873		Sl. Dict.
1935		A.J. Pollock Und. Speaks 27/1: Crib-biter, a gambler who always complains and grumbles.