It's time for a river raft ride on purple water. If you happen to get stuck and your raft leaves without you, just wait for the next one. There are several grates you can climb as a cat, and the Super Bell is in this level. You'll have to complete this level twice to collect everything. Climb up onto the fences and stay up there. You'll find Fire Piranhas up here. There are some trapezes up here. Use two of them to reach the stamp. After a while, the fences will end, so dive to the midpoint. You'll find some Creeper Piranhas here, along with a Green Ring. Collect the coins for the second Green Star, then quickly get back on the raft or wait for the next one. Ahead is a waterfall.
When going down the waterfall, stand in the middle of the raft to collect the coins. At the end of the ride is a warp box. Quickly climb the wall above the warp box to reach the third Green Star, then quickly go through the pipe before the raft disappears under the wall. The warp box leads to the flag.
The first Green Star is near the stamp, but closer to the water. While riding the raft, you'll come across bees and a Red Coin Ring. Past the Creeper Piranha is a clear pipe with the first Green Star. Time your entry into the pipe because it lets out directly over the water. Make sure the raft will be at the other end of the pipe when you will.
The stamp is of Cat Toad napping.