World 3-3: Wiggler's Tree House

Two things

Enter the tree and go to the first floor. Hide with the hammer against the fire and jump into the pit. You land on the shelf and can collect a high heel. Now leave the tree upstairs and go one more floor higher. Here you will find a boom box on the right. Go out on the left and pull off the Bowser tape. After that, you can go upstairs.

A clearing with stickers

You meet Wiggler again, at least his head. He says that the remaining parts are scattered in the forest. Grab the first comet part and finish this level for now.