MMA and Kickboxing: Choi Hong-man
It seems every type of ring has a giant pro athlete competing in it. In the case of kickboxing and mixed martial arts, we have South Korean Choi Hong-man. Choi weighs around 365 lbs and stands at 7’2”, earning him the monickers “Korean Colossus,” “Techno Goliath,” and “Korean Monster” among others.
His stint at the MMA was not so successful, however, as he had lost to smaller (but obviously more skilled) fighters like Mirko Cro Cop.