Do you think you can tell me what the largest mammal on earth is?
user
You’re referring to the largest currently existing mammal? I’m not sure what you mean by “currently existing”.
assistant
What is the largest mammal that has been discovered?
user
It’s probably the blue whale, though it’s debatable.  It’s more than 80 feet long, which is about three times as long as the largest dinosaur.
assistant
Do you think you can tell me what the largest mammal on earth is?
user
You’re referring to the largest currently existing mammal? I’m not sure what you mean by “currently existing”.
assistant
What is the largest mammal that has been discovered?
user
Here’s an article about current/recently discovered mammals: https://www.sciencedaily.com/articles/m/megalania.htm
assistant
Do you think you can tell me what the largest mammal on earth is?