Penguins have an organ near the eye that filters salt from the water out of their system.
Penguins spend a lot of their time in salty waters, and as a result will often drink this.
So how do penguins turn saltwater into freshwater? Penguins don’t actually turn saltwater into freshwater. Rather the sodium chloride is filtered out of their blood stream by a gland called the supraorbital gland. This sits above the eye socket and works to filter out salt. This is then passed out through the penguins bill in the form of brine.