Here's the list of all the bosses in the order you meet them. Note that since there are no names (this does not apply to ALL bosses), we simply decided to give them some (if you have a manual or anything with exact names, please email us about it). The "Club Hits" indicate how many hits with the Club are necessary to defeat the creature and so on (if you have the Bracelet of Power equipped, you'll need of half of the values shown here to defeat the enemy).
Bosses like Graeae and Cerberus have the number of hits for EACH of their forms. And Hades will only become visible after you've taken half of his HP.