E.T. (extraterrestrial) was the main character of an enormously popular Stephen Spielberg film of the same name.
In the movie, a squat extraterrestrial being is accidentally left behind on a scientific expedition studying earthly life. E.T. is found in the forest by Elliot Taylor, a young boy who cares for the creature, rescues it from government agents with dubious motives, and helps reunite it with its fellow alien beings.