Luck Be A Healer. Champions of Rota, #1

A council of goddesses calls a healer, a warrior, a bard, and a monk to fight for them. When an iguana falls at Sean Mulligan's feet on an unseasonably cold Florida day, he thinks it's interesting, especially since things like that don't happen in Chicago where he'll be returning after his spring break. Unable to leave the animal frozen on the ground, he takes it back to his rental and when the creature wakes up he announces that he's an envoy from the god of healing and Sean needs to come with him.
Arguments of finishing med school or even his lease refuses to sway the iguana, who introduces himself as Hank. To appease him, Sean follows orders and soon finds himself on an uncharted Caribbean island and face to face with nine goddesses--all of him want him to heal those who are coming to fight. If he doesn't? He goes back to Chicago and dies as fate intended. Left with no choice, Sean has to make his way in his new life.
His only allies? An iguana named Hank and the goddess Tyche.