Nothing to do with waterproof clothing. Mark you, there is nothing to say that he couldn’t have given his name to a Pacamac.
The brother of legendary people-producer MANCO-CAPAC, he was filled with the desire to create a race of humans. But his attempts at people-making were short-lived as he forgot to provide food and had to face a charge of neglect from the starving masses.
His unpopularity was increased further when, in an attempt to rectify the food situation, he turned the First Woman’s son into an enormous potato. It was downhill all the way for PACHACAMAC after that. And then a vengeful VICHAMA turned all his people into rocks, sparing only the potato.