World 10-4 (Super Mario Maker for Nintendo 3DS)
From the Super Mario Wiki
At the beginning, Mario will get a Super Star. After this, the player will see Bowser and Bowser Jr., winged and enlarged, retreating. The second pit has Lava Bubbles over it. After this, Piranha Plants and Super Mushroom on top of a Propeller Mushroom, which cannot be accessed normally. One is below the ground, so that the Big Piranha Plant can be in a spot not normally in. After this, the player will encounter Green Cheep Cheeps then a Yoshi Egg. After this, Bowser Jr. will come down, and the player must jump on him to get him off the track or else he will go up and never be defeated. A Super Mushroom on a Fire Flower is nearby, and a little bit later. After this, there is a Dry Bones then Winged Coins surrounding a Winged 1-Up Mushroom. Two more Green Cheep Cheeps appear before some Lifts. The Axe is nearby, but if the player waits, a Fire Flower will come down after some time.