A reasonably-sized mechanical arachnid, featuring large-bore hypodermic-tipped legs, that slowly wanders around the lawn injecting water a few inches beneath the surface. The result is a more robust lawn, as the roots dig down to get to the water, with no direct evaporation.
Normally powered from the garden-hose connected to its butt; controlled by solar-celled chippery.
Once or twice a year, set to a different program and with the electric high-pressure pump operating, it can blast aeration holes into the surface.-- FlyingToaster, Jul 14 2015random, halfbakery