Sancho serves as the loyal squire to the main character, accompanying him on adventures. He acts primarily as a comedic foil, offering pragmatic commentary that contrasts sharply with his master's idealistic delusions. His characterization aligns with the archetype from the original Cervantes novel, emphasizing steadfast loyalty even while frequently questioning the impracticality of their pursuits.

In the spinoff series "Don Quixote in Space," the character is transformed into a robot designated S.A.N.C.H.O., accompanying the knight on interstellar missions. This version undertakes linguistic investigations across time and space at the behest of a Castilian empress, expanding his role beyond comic relief to include technical support capabilities. His core dynamic as the grounded counterpart to his idealistic master endures in this adaptation.

The character maintains a static role across all documented media. His background, origins, personal history, and significant character development remain unexplored. His function consistently focuses on supporting the protagonist while providing humorous skepticism about their endeavors.