Pedro serves as a central supporting character and Mendoza's associate, marked by a skinny build and loud-mouthed demeanor. His personality exhibits extreme caution and cowardice, frequently voicing fear in dangerous situations. Yet the promise of gold consistently overrides his reluctance, driving him into perilous adventures alongside Mendoza.

Appearing in Season 1 episodes 1-10, 12, and 14-39, Pedro is rarely separated from Sancho, forming an inseparable comedic duo. Their shared greed and clumsy misadventures generate regular comic relief. Despite self-serving complaints, both display underlying loyalty to Mendoza, following him even when safety is compromised.

As Mendoza’s crew members, Pedro and Sancho assist in navigation and manual tasks aboard the Esperanza and throughout their South American journey. They support the central trio of Esteban, Zia, and Tao but prioritize personal gain over the children's altruistic goals. Initial indifference toward protecting the children shifts during pivotal moments, particularly against the Olmec threat. At the City of Gold, they aid in defending the Mayan village and help mitigate the catastrophic meltdown of the Olmecs’ fusion reactor.

Pedro maintains a relationship of reluctant obedience with Mendoza, openly questioning decisions that prioritize the children’s safety over gold but ultimately submitting to Mendoza’s authority. This loyalty culminates in his return to Spain with Mendoza and Sancho after the events at the first City of Gold. Their departure concludes Pedro’s documented journey, with the group salvaging only a small amount of gold.

His legacy remains tied to his role as a comic yet loyal foil within Mendoza’s group, contributing to both the peril and resolution of their quest while embodying themes of greed tempered by camaraderie.