Imagem de Jesus is a life-sized crucifix housed within the forbidden attic of a monastery, initially appearing as an ordinary wooden statue. The orphan Marcelino discovers this figure despite the prohibition. The statue depicts Jesus Christ nailed to the cross, its detailed craftsmanship conveying suffering and abandonment.

When Marcelino first encounters it, he feels fear but gradually develops empathy, recognizing parallels between its isolation and his own abandonment. He begins offering bread and wine, believing the figure experiences hunger and thirst. These offerings trigger a miraculous transformation: the statue animates, stepping down from the cross to consume the offerings. This animated form engages Marcelino in kind dialogue, serving as both friend and spiritual teacher.

The character demonstrates supernatural abilities beyond animation, including descending from the crucifix at will and possessing full awareness of Marcelino's history and emotional state. During conversations, Jesus explains concepts of maternal love when Marcelino inquires about mothers, stating "They love, they always love." He expresses a thirst interpreted literally and metaphorically, representing spiritual longing. When offering Marcelino a reward for kindness, Jesus learns of the boy's desire to reunite with his deceased mother. In response, he cradles Marcelino, instructs him to sleep, and fulfills this wish by facilitating the boy's peaceful death and implied ascent to heaven. Monks witness this final miracle, observing the statue return to its original position.

In later narrative developments, specifically the animated series' second season, the character's role expands. Following Marcelino's resurrection by his mother, Jesus supports the boy's new mission to aid animals, maintaining their relationship through continued guidance. This depiction consistently presents the figure as a bridge between divine and mortal realms, responsive to innocent faith and compassionate acts.