My favorite demigod story is that of Apo Anno. Anno was a tribal leader who lived in the 12th century in the village of Natubleng in the Philippines. According to legend, Anno’s father, Chief Tugtugaka, was on a hunting trip when he almost killed a deer near a waterfall. The deer belonged to Cuyapon, a young goddess who was bathing in the pool below. Following the near-mishap, the two became good friends and, eventually, lovers. Soon Cuyapon was pregnant with Tugtugaka’s child, but she said the existence of a human-divine child would be frowned upon in her realm. So asked her lover to care for their son, as she promised that she would watch over them in spirit.
Anno came to be regarded as a legendary hunter and a spiritual leader to his people, and Natubleng prospered under him. He was painted with various tattoos covering much of his body as a sign of his social prominence. When he died, he was honored with mummification.
In 1918, Anno’s mummy was stolen from the burial cave by foreign treasure hunters. In 1922 the mummy was spotted in a sideshow at a carnival in Manila. The theft caused an outrage in Natubleng and was blamed for an earthquake, a strong typhoon, and famine in the years that followed. At the carnival, the evening the mummy’s exhibit was opened coincided with a powerful thunderstorm.
In 1984, a local art collector bought a mummy at an auction, which to his surprise turned out to be Apo Anno’s missing mummy. He contacted the National Museum and donated Anno’s remains. Buguias municipality, where Natubleng is now a barangay (county) of, learned of their demigod’s location and reached out to the National Museum for its return. The museum made arrangements, and Buguias pledged to secure his burial cave with a locked gate.
In 1999, Anno’s mummy returned to Natubleng village. His return was celebrated with speeches, a public viewing for the Buguias folk, and elaborate burial rituals. At the end of the celebrations, a rainbow appeared in the sky. The Buguias townspeople took this as a sign of the gods’ approval, and believed Anno’s return was responsible for the prosperity they’ve enjoyed ever since.
In 2019 it was reported that the mummy was experiencing fungal growth, which signaled the onset of decomposition. National Museum representatives believed this was caused by mishandling and exposure of the mummy. While the fungal growth was treatable, Buguias officials decided to move the mummy further into the cave outside the public’s view and installed a replica where it can be viewed. They also began developing the cave area as part of a tourism circuit, which also includes the waterfalls where Tugtugaka and Cuyapon met, fell in love, and pledged to care for Anno in the human realm.
Source: My Quora answer to "Do half-human half-god entities exist in mythology?"