I had a roommate whose dog was a shitnibbler, it was anything but useless. His cat was a shitter and the dog would follow the cat around and eat the turds right as they were coming out if he could catch them, he was really doing his part to keep that place a little less disgusting than it was.
The American Pekin duck (the white ones that look like Donald Duck) is incredibly well suited to being a pet. They can be trained to do their business in a specific spot, they imprint upon their owners as if they were parents, when frightened they return home and when they've gone wearisome, they make great dinner when stuffed between a turkey and a chicken and deep fried in peanut oil.