"Ese pingüino es blanco y negro."
Translation:That penguin is black and white.
It's standard, but very uncommon. In Spanish, when the letter g is followed by either i or e, its normal hard sound (as in gato) becomes soft (as in girar).
To maintain a hard g sound, a silent u can be added (as in guerra). To get both a hard g and an audible u, the u must have an umlaut, or diérisis, placed over it. Thus pingüino is pronounced similarly to penguin in English.
It's worth noting that a diéresis is not necessary if the vowel after the u is an a or an o, like in agua. It only matters for i and e.
It is used everywhere.
gi in Spanish is pronounced heee: gigante
To make the g a "hard" g, we place a u between the g and the i, but gui sounds like Gee (hard 'g'): guisante
To make the u pronounced and not silent we add the two dots. güi sounds like gwee: pingüino