New Super Mario Bros. U: Rock-Candy Mines-3 -- Waddlewing's Nest

This level has several Waddlewings (flying squirrels) and Chomps. Pound the brick blocks to the right of the Chomp on the ground for some coins. There's a red pipe to the right of some Piranha Plants. This will take you to a room with four sets of brick blocks in the floor. The second set of brick blocks from the left has the first Star Coin. Pound the brick blocks to reach it. The other sets have other things. Return to the main level and go up and to the left. If you release the Chomp by pounding its post and it goes to the left, you can reach a hidden area with note blocks and brick blocks. The middle brick block has a 1-up. Go up and over to the left for a hidden area with a P-Switch. This creates a trail of Silver Coins over coins that turned into brick blocks. Follow the trail quickly to reach the second Star Coin. Keep going up to the midpoint, then to the pipe. The pipe leads to an area with a platform that slowly lowers. This part has lots of Waddlewings walking and flying around. Wall jump up the right side for the third Star Coin. There's a Red Coin Ring in the area. Stay to the right to easily reach the flag pipe to the flag. There are Chomps at the bottom you'd have to deal with otherwise.  This opens the path to Rock-Candy Mines-5.