Bring me Hades' guard dog Cerberus and you will atone for your crime
The Call to Adventure
I'll ask to borrow Cerberus and hopefully Hades won't complain
Refusal of the call
Hercules' target Cerberus: The guard dog of the Underworld, Hades' pet
For Hercules's final labor Eurystheus thinks of the harshest task. He wants Hercules to bring Hades's beast Cerberus to him.
Meeting with the Mentor
Super Strength is Hercules' weapon
Hercules is told to bring Cerberus to Eurystheus for the final labor.
Crossing the threshold
Hercules does not refuse the call but instead he accepts it with determination.
Tests, Allies, Enemies
Hades may I borrow Cerberus
Of course, that is if you can defeat him, than no problem
Zeus does not have a mentor but he goes to the oracle of Delphi who tells him to go to King Eurystheus who then gives him the twelve labors. He is given no special weapons but has his inhuman super strength.
Hercules journeys to the underworld to get Cerberus for Eurystheus.
The twelve labors could be considered Hercules's tests. On his way to Cerberus Hercules meets Theseus and Pirithous who were stuck to a bench as a curse for trying to woo Persephone. He ends up ripping Theseus off he bench and brings him with him. Hercules did not have any actual enemies but Hera was responsible for Hercules killing his family and he has to deal with Hades when he gets to the underworld.
Hey Hercules get me off this bench too won't you?