This is the only star in this course that utilizes both the Tiny and Huge Islands. Since the first thing you need to do is on Tiny Island, jump into that painting for now. Once you’re in the stage, Long Jump over to the area with the Piranha Plant, then step on the purple switch to create that path. This will allow you to get to the main area of the course. Your goal as Giant Mario is to get to the very top of the mountain, although you will want to be extra careful on the thin wooden walkway near the summit. Once you’re at the top, perform a Ground Pound in the pool of water to watch it drain (you should hear a little jingle to confirm this).
With the first part of this star out of the way, find the pipe right by the hole that’s shooting out the Big Steelies and use it to go to Huge World (Tiny Mario). The water is drained at the top of the mountain, so that means the hole up there is now accessible. Once you reach the summit, drop into the hole and you will have to face the Wiggler mini-boss. Overall, he is really simple, as all you need to do is jump on his back three times. After the second hit, though, the Wiggler will begin jumping as he’s running around. When the third hit has been dealt, the Wiggler will cough up the star.