the goose that lay, the golden egg.
Here is a classic poem titled "The Goose that Lays the Golden Egg":

In a land of old, where legends were told,
There lived a goose, its feathers of gold.
Each dawn it laid, without fail,
A single egg, beyond the pale.

Its golden hue, a sight to behold,
Yet its worth, a story untold.
For those who sought, with greed in mind,
To seize the goose, its fate unkind.

But heed this tale, for wisdom it bears,
The goose that gives, with no cares.
Its golden eggs, a gift so rare,
To cherish them, beyond compare.

So let this fable, forever remind,
Of greed's folly, and what we find.
The goose that lays, the golden prize,
A lesson learned, before our eyes.