In the animated adaptation "Around the World With Willy Fog," Chiko is a small, anthropomorphic rodent character, often described as resembling a hamster. He is distinguished by his small stature and his signature red dungarees, which make him easily recognizable among the main cast. Chiko is an original character created for the television series and does not appear in the original source novel by Jules Verne.

Chiko's background is rooted in the world of entertainment; he is a former circus artist who worked alongside his best friend, Rigodon. It was during this period that the two formed an inseparable bond. When Rigodon left the circus to seek other employment, Chiko remained with him. The pair faced a period of unemployment together before Rigodon was hired as the new manservant for the gentleman adventurer Willy Fog. Because Rigodon could not bear to part with his friend, he initially smuggled Chiko into Willy Fog's home concealed within his luggage. Chiko's presence was discovered during the team's global expedition when he emerged from hiding to assist Rigodon during a confrontation with the villainous Transfer. After this display of loyalty and courage, Willy Fog immediately accepted Chiko as a permanent member of their travelling party.

In terms of personality, Chiko is a source of lighthearted energy and comic relief for the group. He possesses a childlike and often talkative nature, and his most defining characteristic is his insatiable appetite for snacks and food, which he constantly vocalizes as the group travels to new destinations. This fixation on food often leads to humorous situations, such as when he openly criticizes others' dining habits. Despite his frequently cheerful and sometimes mischievous demeanor, Chiko is prone to showing visible fear when the group finds themselves in dangerous or life-threatening situations. However, this cowardice is consistently overcome by a deep-seated loyalty and bravery; when his friends are in peril, he does not hesitate to spring into action to defend them, sometimes even employing his sharp teeth as a weapon.

Chiko's primary role within the narrative is that of a faithful companion and a comedic foil to the more serious characters. He does not experience significant personal growth or development throughout the series, instead remaining a consistent and reliable source of keck humor and unwavering support for the core group. His most important relationship is with Rigodon, who serves as his anchor and protector. Their bond is depicted as a constant and enduring partnership, with Rigodon often physically shielding Chiko to offer reassurance during frightening moments. Chiko is also deeply loyal to Willy Fog, appreciating the gentleman for accepting him into the household and allowing him to be part of the adventure.

A notable and recurring motif for Chiko is his obsession with an ancient Egyptian sundial, which he was given at the very beginning of the journey. He consults this device constantly and takes great pride in announcing the time to his companions, seemingly seeking their acknowledgment and validation. This quirk, combined with his appetite, forms the core of his interactions with the world around him. Beyond his sharp teeth, his abilities are largely informed by his past as a circus performer, granting him a degree of agility and nimbleness that proves useful on several occasions. Chiko's cultural portrayal has varied in different international versions of the show; while his original characterization had Spanish traits and an Andalusian accent, adaptations often changed his nationality or gave him a different accent, such as Italian or Mexican. Chiko also appears in the sequel series "Willy Fog 2," joining his friends on further adventures adapted from other Jules Verne novels, where he retains all of his trademark traits.