As the name of this level suggests, you will be introduced to the Piranha Creeper here. It is a large Piranha Plant that is connected to a vine, which will move back and forth out of a specific spot. If you jump on top of the head, or hit it with a power-up, then it will retract a little bit. Force it to retract back to its origin point and the Piranha Creeper will be defeated, leaving behind a few coins. Head past the first wave of these enemies to a ?-Block that has a power-up (a Fire Flower, if big). Notice that the blue Piranha Creeper is sleeping, but will wake up to return to its original position if attacked.
March through the first area and defeat the Piranha Creeper blocking the pipe to the next zone. Inside the cave, right past the first Piranha Creeper will be a Mystery Box, so dive into it. Inside, you will have 10 seconds to reach and collect the Green Star, so bounce up to it via the Piranha Creepers to net yourself Green Star #1. After exiting, you will find the Checkpoint Flag right after the next Creeper. Just beyond that, two Piranha Creepers will be moving through water, but you will want to dive underwater to find Green Star #2. A little past those Creepers will be one more that is coming out of the way.
You will want to jump off of the Piranha Creeper and “into” the wall to find a secret passage, which leads to the level’s Stamp. Use the pipe at the end to reach the final area. You should spot a Roulette Block as soon as you exit, so hopefully you can get something good, like a Super Leaf if possible, as it makes navigating the area a little bit easier.
The rotating platforms ahead have a Green Star Ring that you’ll want to activate, but it’s a good idea to take out the Piranha Creepers first. This makes it so you can easily run through this tight area, grabbing the green coins and ultimately, claiming Green Star #3 . At the end, use the pipe to reach the Goal Pole where you can bounce off a Piranha Creeper to cap it.