This novel was writen in his later lifePip, a boy of the marshes, is being "raised by hand" by his shrieking harridan of an older sister and her seemingly doltish husband, the blacksmith Joe Gargery.
It's found over marshes or sometimes at sea, but it's spawned folklore the world over about a character named Jack who fooled the devil, was mean to the devil, bested the devil.
As the marshes and forests of Germania lie beyond the empire's road system the men must build causeways and bridges to make headway— something they've recently spent more time doing than fighting.
Even when Native Americans lived out here, it was also named 'The River of Grass' because the sawgrass on the outside area dominates the majority of the area on the marsh.
It can take out one of our apex predators which are alligators and crocodiles, and then they'll take down some of the other native animals that are small mammals: some of the rats, the mice, the marsh bunnies.