Pu-os, the northwestern most barangay of Cabugao is along the coast area of China Sea. Unlike all other barrios of Cabugao, it is the only barrio that has a school along the national highway.
There are four sitios in the barangay, namely: Pug-os West which is West of the national highway, Pug-os East which is opposite it, and the two adjacent barrios of Bessang and Padual.
The native name of this barrio was Balaywak which means house of crows for it used to be the abode of black birds called crows or wac during the olden days.
One day, a group of American soldiers hiked from the Poblacion of Cabugao to this place to experience the cool breeze of the sea. The place was still then wilderness where wild fruit trees grew, most of which were blackberry trees. These trees were covered with big ants called aboos, for they like to eat the fruits. American soldiers like the fruits very much. When they climbed the trees, the ants bit them and the Americans nearly fell. These Americans asked the name of these insects from some boys who were pasturing their carabaos nearby. In answer, the boys told them that they were aboos. As these aboos bit them, the soldiers shouted Pug-os! Pug-os! Pug-os!. The boys only laugh at them. They tried to correct them but still they kept on shouting Pug-os! Pug-os! Pug-os! Since then it was named Pug-os.