work like a horse

and the like

And other similar items; et cetera.

be like

To say.

beat a dead horse

To persist or continue far beyond any purpose, interest or reason.

built like a brick outhouse

Synonym of built like a brick shithouse.

built like a brick shipyard

Synonym of built like a brick shithouse.

built like a brick shithouse

Of a man, having a muscular body, particularly with well-developed muscles of the chest, arms and abdominals.

busy work

Work or activity performed with the intention or result of occupying time, and not necessarily to accomplish something productive; routine work of low priority undertaken for the sake of avoiding idleness.

charley horse

A muscle cramp, usually a strong one, in the thigh, leg, arm, or core.