There's one surefire way to get rid of the grass in your lawn: dig a big hole, cover it with a large sheet of plastic, and fill it with water. That's essentially how you make a wildlife pond, but the results are much more rewarding than this description may suggest. If built correctly, wildlife ponds can support a variety of living things, both plants and animals. Shallow shelves around the edge of the pond can be sewn with aquatic vegetation, while native grasses planted at pond's edge will invite newts, frogs, and other amphibians to take up residency. You can also expect to see many other animals, including snakes, raccoons, songbirds and dragonflies.
While installing a wildlife pond can be pretty hard work, once established, it will basically take care of itself. The plants don't require watering or mowing, and fertilization is discouraged because it could actually harm the very wildlife you're trying to attract. A wildlife pond can still be water-intensive, though, as evaporation forces you to top it off every once in a while. For this reason it may not be a good choice if you live in a hot, dry climate.