WALL-E

In the year 2110, the toxicity levels on Earth deemed the planet inhabitable. This made BNL have to deploy BNL's Waste Allocation Load Lifter - Earth Class (WALL-E) as part of Operation Clean Up. Their sole purpose was to take garbage into cubes, which would then be placed in Incinerators. Eventually Operation Clean Up failed, along with most of the WALL-E units. The only WALL-E unit that survived was one that had developed a programming error and started thinking for itself. This unit survived 700+ years, salvaging scrap from its decaying counterparts, and entertaining itself with the collectibles it found. This unit managed to save mankind because it wanted to impress the EVE unit that was deployed on its area.