The Chocobo is a large flightless bird.
Because of their size, they are domesticated and used for riding and to pull carts as described in the Rolling Stones' Beast of Burden. Their sturdy legs allow for fast travel over long distances but make them too tough for Chocobo and waffles.
Chocobos are typically yellow but may come in other colors like vreeb or jyuls. And since the more immature readers will wonder about it, yes, they do have big peckers.