1. slang Anyone forced or employed to dig trenches or ditches. Prisoners in that area were forced to work as sewer hogs until about 1945, having dug drainage ditches alongside the highway from one end of the state to the other. My father wasn't very proud of having to work as a sewer hog, but it put food on our table as kids, and none of us ever cared more than that.

2. One of a breed of wild pigs rumored in urban legend to inhabit the sewers of Hampstead, London. My brother always told me scary stories about the sewer hogs to keep me away from open manhole covers.