Pedro, sometimes called Peter, tends the village goats in the Swiss Alps. He resides in a modest hut between Dörfli and his grandfather's mountain cabin with his mother Brigitte and his blind grandmother. Sullen and rebellious, Pedro lacks formal education and is illiterate, much like Heidi before Frankfurt. His daily duty is herding goats to the high pastures, where he forms a vital friendship with Heidi upon her arrival. This bond anchors his interactions, yet he displays intense jealousy when Heidi's focus turns to others, especially Clara Sesemann during her visit.

Pedro's blind grandmother treasures a book of psalms she cannot read. His illiteracy prevents him from reading it to her, a limitation persisting until Heidi learns to read in Frankfurt. Heidi later reading the psalms provides the grandmother profound emotional comfort, indirectly underscoring Pedro's shortcoming. His jealousy erupts when he impulsively pushes Clara's wheelchair down the mountain, destroying it. Driven by resentment over Heidi and Clara's closeness, this act later fills him with guilt, compelling him to confess. The incident inadvertently forces Clara to attempt walking, leading to her gradual recovery.

Demonstrating growing maturity and skill, Pedro builds his own sled and wins a village race. His relationship with Heidi and her grandfather develops, particularly after they move to the village in winter so both children can attend school. This shift fosters greater social integration for Pedro, aligning with the narrative's theme of community bonding. His character evolves from isolation and emotional impulsiveness toward increased responsibility and communal participation, though his core loyalty to Heidi and occasional jealousy endure.

The OVA *Alps no Shoujo Heidi: Alm no Yama Hen* presents Pedro's story from the original television series without adding new developments or background beyond the established narrative. His portrayal across all media consistently focuses on his role as Heidi's friend, his family duties, and his emotional journey from resentment through remorse toward partial growth.