我们在花园里发现了一个巨大的西瓜，简直是个巨无霸。

We found a ___whopper of a watermelon in the garden.

他说他曾经环游世界一周只用了三天，这简直是个弥天大谎。

He claimed to have traveled around the world in just three days, which was a total ___whopper.