possibly plankton
The largest and heaviest living creature on earth is the blue whale.
I believe the biggest living creature that scientists know of right now is the Blue Whale.
Man is probably to answer to both.
Some people don't believe this, but most do believe it these days. Not a creature, but a beast! Please define 'most'. I know that most people of my acquaintance do not believe that anyone returns to a living existence on Earth after death.
It would be sharks. They outlived dinosaurs!
Every living creature on earth responds to the messages implicit in the play of light and color.
a tiger
Giraffe
human female's
Man.
The first living things on earth were microbes, tiny one-celled creatures.
Dart Frog