I don't know about nine brains, but:
Octopuses have three hearts. Two of the hearts work exclusively to move blood beyond the animal’s gills, while the third keeps circulation flowing for the organs. The organ heart actually stops beating when the octopus swims, explaining the species’ penchant for crawling rather than swimming, which exhausts them.
Read more: http://www.smithsonianmag.com/science-n ... So6hE7Q.99
Cats with nine lives are another rumor