Luis is a Secret Monkey found in the Viva Apespania level of Ape Escape 2. It is located in the bull fighting arena segment. When you get to the bull fighting arena segment of the level you should see a big bull fighting arena in front of you with large wooden doors. To get the monkey Luis you must be on the ledge located on the right of the wooden doors. Once you are on the ledge look towards the arena and there should be a wooden window, hit the wall to the right of the window with the Magic Punch to find Luis.
Stomach fullness: 5/5
I just can't control myself!