Turnspit Dog

One who has all the work but none of the profit; he turns the spit but eats not of the roast. The allusion is to the dog used formerly to turn the spit in roasting. Topsel says, “They go into a wheel, which they turn round about with the weight of their bodies, so dilligently … . that no drudge … . can do the feate more cunningly.” (1697.)