The Final Fantasy Adventure script, and recent English Art of Mana, use masculine pronouns for Chocobo, while the English localization of Adventures of Mana uses feminine.
A boy in Menos mentions that the village used to see many chocobos around the area, even seeing an egg in a forest up north. Sumo ventures into the forest and locates the egg. The egg starts to hatch and a chocobo emerges from the egg. Sumo wonders what the creature is. When he leaves, the newborn follows him. Eventually, Sumo agrees to have the chocobo tag along on his journey.
Chocobo is left behind at the entrance of Mt. Rocks. After Sumo's confrontation with Julius, he finds himself left for dead in the middle of the Crystal Desert. He's rescued by Chocobo, who carries him to Ish. Sumo learns from Dr. Bowow that chocobo's leg was wounded and he mechanized it and gains the ability to go on water. Dr. Bowow also names him Chocobot. Both Sumo and Chocobot head to their next destination, Wendel.
When they reach Lorim, Sumo learns from the king that a monster by the name of Kary has frozen the townfolk. Both Sumo and Chocobot venture towards the monster's lair. Unfortunately, Sumo can't take Chocobot with him further when they reach the snowfields due to it being too cold. Chocobot stays behind while Sumo proceeds further.
Chocobot is left outside of Dime Tower. Sumo becomes separated from Chocobot when the tower falls down.
After Julius's defeat, Sumo and Chocobot return to the forest to the north of Menos and they meet a female chocobo. Sumo and Chocobot part ways.
When asked, it will allow Sumo to ride on its back. While riding, no enemies will be able to hurt Sumo. Once it has become a Chocobot, the chocobo will be able to cross rivers and ocean. The chocobo will also be able to heal Sumo from the Moog status if asked when he's a moogle.
Chocobo appears in the version available via Final Fantasy Portal App.
食う / くう / kuu is a rough way to say "eat", whose volitional casual form is 食え / くえ / kue ("let's scoff 'em down!"), leading to Kweh!