Here is Roy Hibbert doing some MMA training that involves hitting him with padded sticks that could conceivably be long salamis if you squint. The joke is in the reveal that his training partner has to stand on a gigantic box to be as tall as Roy while he’s doing tiny chops with the padded sticks. Good joke.
Here is Roy Hibbert after playing paintball. The joke is that he’s not standing on anything. Great joke.
Based on these two pieces of evidence, it’s quite possible that Roy Hibbert is the NBA’s foremost practitioner of close-range combat. As long as you’re fighting him with padded attacks and ammunition that can’t actually hurt him, no one stands a chance.