Blue Whale
elephant
I believe the biggest living creature that scientists know of right now is the Blue Whale.
on earth
The largest and heaviest living creature on earth is the blue whale.
The elephant is the biggest living land animal on the earth.
Elephants are probably the largest living mammals on earth. They don't have any natural predators that can attack a full grown elephant. However, lions and packs of hyenas have been known to attack an injured or extremely old elephant or an elephant calf that has strayed away from its herd. Humans are the biggest enemies to elephants. Armed with guns hunters and poachers are the biggest threat to elephant numbers.
the African elephant
On earth
Because of Hunting. Elephants are probably the largest living mammals on earth. They don't have any natural predators that can attack a full grown elephant. However, lions and packs of hyenas have been known to attack an injured or extremely old elephant or an elephant calf that has strayed away from its herd. Humans are the biggest enemies to elephants. Armed with guns hunters and poachers are the biggest threat to elephant numbers.
A Whale and I do believe they are also the biggest mammal on earth too.
Alive, or ever to have lived, the blue whale is the largest creature. Larger than the largest dinosaur that we know of, it has a heart the size of a car, a tongue as big as an elephant, and blood vessels large enough that you could swim through them. This is worth watching...http://www.extremescience.com/BlueWhale.htm
possibly plankton