Preheat the oven to 350 degrees F (175 degrees C).

Season rabbit pieces with pepper and salt.

Heat vegetable oil in a large skillet over medium-high heat. Add rabbit; cook in hot oil until brown on all sides. Place in a 9x13-inch baking dish.

Combine onion, water, ketchup, Worcestershire sauce, sugar, paprika, and garlic in a medium bowl; mix well, then pour over rabbit.

Bake uncovered in the preheated oven, basting frequently, until very tender, about 90 minutes. An instant-read thermometer inserted into the meat nearest the bone should read at least 160 degrees F (72 degrees C).