https://cavestory.fandom.com/wiki/Quote

Quote (クォート kuōto) also known as Mr. Traveler, is the main character of Cave Story. He is a "soldier from the surface" - a powerful combat android who was made to find and destroy a magical artifact known as the Demon Crown. He is the counterpart of Curly Brace, who was designed for the same purpose.

Despite being a durable combat android, he is incredibly humanlike, being able to do things like eat food, and displaying limitations such as needing to breathe.