Choco is a Chinese criminal and one of the people responsible for the martyrdom of San Pedro calungsod.
Choco began spreading rumors that the baptismal water used by missionaries was poisonous. As some sickly Chamorro infants who were baptized eventually died, many believed the story and held the missionaries responsible. Choco was readily supported by the macanjas (medicine men) and the urritaos (young males) who despised the missionaries.
In their search for a runaway companion named Esteban, Pedro and San Vitores came to the village of Tumon, Guam on April 2, 1672. There they learnt that the wife of the village's chief Mata'pang had given birth to a daughter, and they immediately went to baptize the child. Influenced by the calumnies of Choco, Chief Mata'pang strongly opposed; to give him some time to calm down, the missionaries gathered the children and some adults of the village at the nearby shore and started chanting with them the tenets of the Catholic faith. They invited Mata'pang to join them, but he shouted back that he was angry with God and was fed up with Christian teachings.
Determined to kill the missionaries, Mata'pang went away and tried to enlist another villager, a pagan named Hirao. The latter initially refused, mindful of the missionaries' kindness towards the natives, but became piqued and eventually capitulated when Mata'pang branded him a coward. While Mata'pang was away from his house, Father Diego and Pedro baptized the baby girl, with the consent of her Christian mother.
When Mata'pang learnt of his daughter's baptism, he became even more furious. He violently hurled spears first at Pedro, who was able to dodge them. Witnesses claim that Pedro could have escaped the attack, but did not desert Father Diego. Those who knew personally Pedro considered his martial abilities and that he could have defeated the aggressors with weapons; Father Diego had however banned his companions from bearing arms. Pedro was struck with a spear in the chest and fell to the ground; Hirao immediately charged towards him and finished him off with machete blow to the head. Father Diego quickly absolved Pedro before he too was killed.
Mata'pang took Father Diego's crucifix and pounded it with a stone whilst blaspheming God. Both assassins then undressed the corpses of both Pedro and Father Diego, tied large stones to the feet, and after loading these on their proas, dumped the bodies out in Tumon Bay.