The one you see in the gym? If you lift enough weights in front of him, and then later compliment and grapple him in battle you can get a scene with him. If he's too big, he won't appear in the gym though, so you may need to get a black xp potion and use it on him. If you got the xp potion from the bar and used it one the knight, you can get more from the Turtle which will also lead to you getting the black xp potion