There's a very specific spot that the Panda appears.
When you enter the Konahana Low area (the one with the hand fishing lake), if you are coming from the Konahana village side, run all the way to the left of the area just before exiting the screen, and jump up the hill steps until you come to a Zipline.
Press the A button to use the zipline and ride it all the way down. When you get to the area at the end of the Zipline, run to the left, and that is where the Panda hangs out. If you don't encounter a Panda there after 9:00pm, use the slide and exit the screen, and return to that area, and you will most probably see one there.