The Book of Life
Xibalba is established as the ruler of The Land of the Forgotten, a duty he has grown to hate due to the dreary conditions, especially contrasted with the festive nature of his wife's domain, The Land of the Remembered. Prior to the events of the film, Xibalba had made a bet wherein he cheated, resulting in not only his ruling state, but also his estranged relationship with La Muerte, with whom he seeks to reconcile.Determined to escape his role, Xibalba proposes another wager with La Muerte, this time concerning a budding love triangle between two friends, Manolo and Joaquín, and their mutual female friend, María. Xibalba bets that the latter will marry María in the future, with the condition that he shall rule The Land of the Remembered if he wins. To ensure a chance at victory, he, in the form of an old beggar, provides Joaquín with the Medal of Everlasting Life, which grants its wearer functional immortality by making them unable to be harmed or killed.Years later, Manolo and Joaquín both unsuccessfully attempt to woo María, although Manolo manages to make a heartfelt connection with her. Determined to not lose the wager, Xibalba summons a two-headed snake and sends it to bite Maria, putting her into a coma-like state, until she would conveniently reawaken once she was with Joaquín. With this, Xibalba, in the same old beggar form as before, takes advantage of Manolo's grief-stricken belief that Maria is dead to manipulate him into accepting his "help" to find María. He has the two-headed snake bite Manolo twice, which does kill him. With Manolo dead and María set to wed Joaquín to ensure the protection of their village, Xibalba declares a victory on the wager. When Manolo goes forth to find La Muerte so he may find María, Xibalba is sitting in her stead.Angered by his deception, Manolo accepts the challenge of descending into The Land of the Forgotten to find La Muerte. In the meantime, the notorious bandit Chakal, who previously had the Medal of Everlasting Life until Xibalba stole it back, is alerted to its presence on Joaquín and declares that his forces will take the village on the Day of the Dead.Despite the arduous journey, Manolo, aided by his deceased mother and grandfather, reaches The Land of the Forgotten and approaches La Muerte. Once his deception is revealed, Xibalba is summoned and confronted by an angry La Muerte for his cheating, but he stubbornly refuses to back down until Manolo offers him a wager: Xibalba will give him a task that Manolo must face, and if Manolo wins, Xibalba will grant him life to get back to the land of the living; but if Xilbalba wins, he will get to rule both the Lands of the Remembered and Forgotten and Manolo will be forgotten forever. Finding this to be amusing, Xibalba accepts and takes advantage of Manolo's wager to attempt another easy victory by forcing Manolo to fight every bull slain and defeated by Manolo's family, believing that it to be his worst fear. However, Manolo reveals that his true fear was being himself, which he overcomes when he sings the giant demonic bull constructed of all the other bulls into a peaceful state.Seeing Manolo triumph in this wager, Xibalba is completely speechless and initially upset over his defeat, but decides to accept it and grants Manolo a return to life as promised, so that he may help defeat Chakal and be reunited with María. Seeing both the living and dead reunited to take down Chakal and his forces, Xibalba abandons his cheating ways and successfully reconciles with La Muerte.During the frame story, a tour guide named Mary Beth guides a group of children to the eponymous Book of Life to tell them the story. She is eventually revealed to be La Muerte in human disguise. Xibalba also appears in the guise of a museum security guard, showing his true form to share a tender moment with La Muerte.
Contrasting the lively colored and adorned La Muerte, Xibalba carries a grim and darker appearance befitting his role as the ruler of the Land of the Forgotten. True to the Day of the Dead iconography, Xibalba resembles a skeleton, given wings and a crown. This connects with the origin of his name as the underworld of K'iche Maya mythology, roughly translated as "the land of fear". It also highlights his more sinister qualities, such as his determination to win his wager between himself and La Muerte through underhanded methods. Xibalba understands humans as petty, assuming that María would be won over by Joaquín's use of the Medal. One condition of the wager noted that he loved to mess with the lives of mortals, as seen when he blows out the memorial candles and attempts to take the life of an old man. He also does not take lightly to anyone who challenges him, as seen with Manolo's angry declaration that he will expose him to La Muerte. This prompts Xibalba to respond that no one who talks to him in such a manner survives.Nevertheless, Xibalba sincerely loves his wife and seeks to reconcile with her. Despite this, he still takes advantage of her willingness to engage in wagers in order to gain attempts at power. However, in the end, he manages to put these negative qualities aside so that he can be with her once again. By the present day, their relationship is still shown in a positive light, suggesting that he has redeemed himself once and for all.