In one, Thetis was the daughter of the centaur Chiron, not of Nereus. In another strange account, known only from a fragmentary poem by Alcman, Thetis appears to be one of the first—perhaps even the very first—being to come into existence, together with or just before the abstract personifications Tekmor (“End”) and Poros (“Path”). More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.