The term "blue-green giants" is not a standard astronomical term. There are no planets commonly referred to by this name.

It's possible you're thinking of:

* Blue giants: These are stars that are much hotter and larger than our Sun, often with a bluish hue.

* Gas giants: These are planets composed primarily of gas, like Jupiter and Saturn. They are typically much larger than rocky planets.

Therefore, no two planets are known as "blue-green giants" in astronomy.