Mixed Martial Arts Gym "Wild Kingdom" is a stage in Tekken 6's Scenario Campaign mode. King and Craig Marduk are fought here simultaneously. Clearing this stage and defeating King and Marduk will unlock them in Scenario Campaign and Arena.
"Today we visited a mixed martial arts gym. The two co-owners, one of them not easily classified as "human", were once bitter rivals. From enemies to allies, it would seem. But I am still detecting alarming levels of cortisol in the air".