Equipped with innate skill, evolved discipline and unmatched dedication, the UFC's current champions are some of the most unbeatable figures in mixed martial arts today.
Not only have they showcased their masterful arts in the past, but through various championship trials and tribulations, they've evolved into stronger, smarter and more versatile animals.
But as we tread deeper into 2013, their spots atop their respectful thrones are sure to be put in danger.
It's up to them to outwork and overcome the competition currently nibbling at their ankles. But with cunningly hidden strength at their disposal, they should be able to withstand the test of time.