Snake

In the present day the grass is thick and there is a lot of life, the sun is still a main-sequence yellow star, and the snake is still emerald green. We are now 150 million years in the future. In 150 million years the sun will be a red giant, the snake is smaller to preserve energy, as there is not as much food, most of the trees are dead, there is no ice left, and humans are gone because it got too hot out. I came to this conclusion because global warming made it too hot and the sun getting so big didn’t help either but that's just how things work. Humans aren't gone though, we went to mars, which is now habitable, but that’s beside the point. There are few creatures left but the few that are have adapted to some tough conditions.