Following the Nepali New Year, one of the festivals that occurs in the Thimi area is the multi-day Balkumari festival. It's said that there is a festival, pilgrimage, or other ceremonial event for practically every day of the year for Nepal's complex cultural traditions.
In this event, a volunteer in a spiritual trance gets his tongue pierced with an iron spike. Good fortune to the village and to the volunteer will follow should he succeed in spending the whole day thus spiked. Interestingly, I've found one article referring to this tradition but it indicates no written history of it. In his article, the Tongue Boring Festival of Thimi, author Subhash Ram relates its traditional beginnings. I’ve paraphrased them here:
Once upon a time, Thimi was haunted by man-eating demons. The demons scared the living daylights out of the people, who eventually petitioned the royal palace to protect their lives. A Tantrik said that the demons could be punished by the charisma of lord Bhairab, so rituals were performed, and the demons were caught.
As punishment, in front of Lord Bhairab, with permission of the king, their tongues were pierced. Each of them was made to carry 108 flaming torches on the shoulder with small bells, and all were made to walk around the country. Afterward, each demon was exiled from the country. As a reminder to be good neighbors, and that those who distresses others will be punished in this way, the Tongue Boring festival is celebrated every year. But apparently now only one person volunteers to be the demon.....