[2][3] During World War II, he directed training films for the United States Army while continuing to produce Sunday Gordo cartoons.

[2] Although Arriola did not visit Mexico until 1961, he used the human and animal characters of his strip to introduce Mexican culture to readers throughout the world.

[1] Gordo was initially designed to be a Mexican version of Li'l Abner, with a highly caricatured style and a lazy overweight title character who spoke in heavily accented English and took naps under a tree wearing a sombrero.

[1] The character reflected popular conceptions of Mexicans at the time, particularly Leo Carrillo's portrayal of The Cisco Kid's sidekick, Pancho, on television and film.

[4] A much thinner and contemplative Gordo eventually became a flirtatious tour guide, whom Arriola often described as an "accidental ambassador" for Mexican culture.