Mamá Coco

Socorro, better known as Mamá Coco, is the titular character in Pixar's 19th full-length animated feature film, Coco. Although her screen time in the movie is minimal her importance is extremely significant.

History
Mamá Coco is introduced as the daughter of Imelda and an unnamed musician who left Imelda with Coco after the latter decided to pursue a career in music. Because of this, an embittered Imelda enforced a ban on music in her family and raised Coco herself. In present day, Coco is the beloved great-grandmother of Miguel, and is the only member who listens to Miguel's hopes and dreams (albeit having trouble remembering things due to her old age). Despite the outcast status of her father among the Riveras, Coco still remembers her father and thinks of him fondly. However, her declining health and memory is a growing concern for her daughter Abuelita Elena, who becomes more worried and protective of her mother.

On Día de los Muertos, Coco is overseeing her family's ofrenda, on top of which is the portrait of Coco with her parents, including Coco's disgraced father. After Dante accidentally shakes the ofrenda and causes the portrait to shatter, Miguel spots the man in the portrait holding a guitar identical to the guitar of Ernesto de la Cruz. Seeing the portrait causes Mamá Coco to react and confirm the figure is her father. Miguel, believing Coco meant that de la Cruz is her father, takes this as a sign to fulfill his dream of becoming a musician. Unfortunately, this leads to an argument between Miguel and the rest of the family, which in turn leads Miguel to try stealing Ernesto's guitar for himself. Because of his hasty act, Miguel becomes cursed and transformed into a spirit.

While in the Land of the Dead, Miguel learns that Héctor is Coco's real father, not Ernesto, and Coco is the last living person who remembers him. Meanwhile, back in the Land of the Living, Coco's mind, including the memories of Héctor, is fading, and Héctor will too if Coco completely forgets. Miguel, together with Héctor, Imelda, and the deceased Riveras, try to send Héctor's photo back with Miguel so that Coco can remember him. In the process however, the photo is lost, and Miguel is sent home empty-handed. Miguel returns to the Rivera residence and, despite Abuelita's objection, bursts into Coco's room to see Coco has become catatonic.

But Miguel remembers the special song Héctor sang to Coco; with Héctor's guitar, he plays "Remember Me / Recuerdame" to Coco, which bring Coco back to her senses. Revitalized by her father's music finally motivates Coco to reveal her father's identity, the letters he sent to her as a child, and the torn picture of Héctor from the family portrait. The evidence grants Héctor the recognition he was robbed of from Ernesto and the Riveras accept him back into the clan.

Some time before the next Dia de los Muertos, Coco passes away and her picture is also placed on the ofrenda. Reunited with her parents in the Land of the Dead, the deceased Coco accompanies them on their visit to the Land of the Living. Coco stands next to Abuelita as they watch Miguel perform a song to the family.

Trivia

 * Mamá Coco was born in 1918.
 * As the film takes place in present day, Coco was 99 years old at the time of Coco. This is confirmed by Lee Unkrich, who revealed Coco passed away at 100 years old.
 * Since Hector was born in 1900 and Imelda a year before him, it is hinted that Coco's parents may have been 18 and 19 years old respectively when she was born.
 * Coco's last name is Rivera. Her daughter's name is Elena, but her husband's last name is Rivera. This is currently an unsolved error, but it may be that Franco and Abuelita Elena were cousins.
 * Miguel's younger sister Socorro is named after Mamá Coco.